diff --git a/src/libslic3r/FilamentGroup.cpp b/src/libslic3r/FilamentGroup.cpp
index d49399a40..e2aa18bce 100644
--- a/src/libslic3r/FilamentGroup.cpp
+++ b/src/libslic3r/FilamentGroup.cpp
@@ -3,6 +3,7 @@
 #include <queue>
 #include <random>
 #include <cassert>
+#include <sstream>
 
 namespace Slic3r
 {
@@ -52,6 +53,161 @@ namespace Slic3r
         return true;
     }
 
+    static int calc_color_distance(const Color &src, const Color &dst)
+    {
+        double rmean = (src.r + dst.r) / 2.f;
+        double dr = src.r - dst.r;
+        double dg = src.g - dst.g;
+        double db = src.b - dst.b;
+
+        return sqrt((512 + rmean) / 256.f * dr * dr + 4 * dg * dg + (767 - rmean) / 256 * db * db);
+    }
+
+    // clear the array and heap,save the groups in heap to the array
+    static void change_memoryed_heaps_to_arrays(FilamentGroupUtils::MemoryedGroupHeap& heap,const int total_filament_num,const std::vector<unsigned int>& used_filaments, std::vector<std::vector<int>>& arrs)
+    {
+        // switch the label idx
+        arrs.clear();
+        while (!heap.empty()) {
+            auto top = heap.top();
+            heap.pop();
+            std::vector<int> labels_tmp(total_filament_num, 0);
+            for (size_t idx = 0; idx < top.group.size(); ++idx)
+                labels_tmp[used_filaments[idx]] = top.group[idx];
+            arrs.emplace_back(std::move(labels_tmp));
+        }
+    }
+
+    Color::Color(const std::string& hexstr) {
+        if (hexstr.empty() || (hexstr.length() != 9 && hexstr.length() != 7) || hexstr[0] != '#')
+        {
+            assert(false);
+            r = 0, g = 0, b = 0, a = 255;
+            return;
+        }
+
+        auto hexToByte = [](const std::string& hex)->unsigned char
+            {
+                unsigned int byte;
+                std::istringstream(hex) >> std::hex >> byte;
+                return static_cast<unsigned char>(byte);
+            };
+        r = hexToByte(hexstr.substr(1, 2));
+        g = hexToByte(hexstr.substr(3, 2));
+        b = hexToByte(hexstr.substr(5, 2));
+        if (hexstr.size() == 9)
+            a = hexToByte(hexstr.substr(7, 2));
+    }
+
+    std::vector<int> select_best_group_for_ams(const std::vector<std::vector<int>>& map_lists, const std::vector<unsigned int>& used_filaments, const std::vector<std::string>& used_filament_colors_str, const std::vector<std::vector<std::string>>& ams_filament_colors_str)
+    {
+        assert(used_filaments.size() == ams_filament_colors_str.size());
+        // change the color str to real colors
+        std::vector<Color>used_filament_colors;
+        std::vector<std::vector<Color>>ams_filament_colors;
+        for (auto& item : used_filament_colors_str)
+            used_filament_colors.emplace_back(Color(item));
+
+        for (auto& arr : ams_filament_colors_str) {
+            std::vector<Color>tmp;
+            for (auto& item : arr)
+                tmp.emplace_back(Color(item));
+            ams_filament_colors.emplace_back(std::move(tmp));
+        }
+
+
+        int best_cost = std::numeric_limits<int>::max();
+        std::vector<int>best_map;
+        for (auto& map : map_lists) {
+            std::vector<std::vector<Color>>group_colors(2);
+
+            for (size_t i = 0; i < used_filaments.size(); ++i) {
+                if (map[used_filaments[i]] == 0)
+                    group_colors[0].emplace_back(used_filament_colors[i]);
+                else
+                    group_colors[1].emplace_back(used_filament_colors[i]);
+            }
+            int tmp_cost = 0;
+            for (size_t i = 0; i < 2; ++i) {
+                if (group_colors[i].empty() || ams_filament_colors[i].empty())
+                    continue;
+                std::vector<std::vector<float>>distance_matrix(group_colors[i].size(), std::vector<float>(ams_filament_colors[i].size()));
+
+                // calculate color distance matrix
+                for (size_t src = 0; src < group_colors[i].size(); ++src) {
+                    for (size_t dst = 0; dst < ams_filament_colors[i].size(); ++dst)
+                        distance_matrix[src][dst] = calc_color_distance(group_colors[i][src], ams_filament_colors[i][dst]);
+                }
+
+                // get min cost by min cost max flow
+                std::vector<int>l_nodes(group_colors[i].size()), r_nodes(ams_filament_colors[i].size());
+                std::iota(l_nodes.begin(), l_nodes.end(), 0);
+                std::iota(r_nodes.begin(), r_nodes.end(), 0);
+                MCMF mcmf(distance_matrix, l_nodes, r_nodes);
+                auto ams_map = mcmf.solve();
+
+                for (size_t idx = 0; idx < ams_map.size(); ++idx) {
+                    if (ams_map[idx] == -1)
+                        continue;
+                    tmp_cost += distance_matrix[idx][ams_map[idx]];
+                }
+            }
+
+            if (tmp_cost < best_cost) {
+                best_cost = tmp_cost;
+                best_map = map;
+            }
+        }
+
+        return best_map;
+    }
+
+
+    void FilamentGroupUtils::update_memoryed_groups(const MemoryedGroup& item, const double gap_threshold, MemoryedGroupHeap& groups)
+    {
+        auto emplace_if_accepatle = [gap_threshold](MemoryedGroupHeap& heap, const MemoryedGroup& elem, const MemoryedGroup& best) {
+            if (best.cost == 0) {
+                if (std::abs(elem.cost - best.cost) <= ABSOLUTE_FLUSH_GAP_TOLERANCE)
+                    heap.push(elem);
+                return;
+            }
+            double gap_rate = (double)std::abs(elem.cost - best.cost) / (double)best.cost;
+            if (gap_rate < gap_threshold)
+                heap.push(elem);
+            };
+
+        if (groups.empty()) {
+            groups.push(item);
+        }
+        else {
+            auto top = groups.top();
+            // we only memory items with the highest prefer level
+            if (top.prefer_level > item.prefer_level)
+                return;
+            else if (top.prefer_level == item.prefer_level) {
+                if (top.cost <= item.cost) {
+                    emplace_if_accepatle(groups, item, top);
+                }
+                // find a group with lower cost, rebuild the heap
+                else {
+                    MemoryedGroupHeap new_heap;
+                    new_heap.push(item);
+                    while (!groups.empty()) {
+                        auto top = groups.top();
+                        groups.pop();
+                        emplace_if_accepatle(new_heap, top, item);
+                    }
+                    groups = std::move(new_heap);
+                }
+            }
+            // find a group with the higher prefer level, rebuild the heap
+            else {
+                groups = MemoryedGroupHeap();
+                groups.push(item);
+            }
+        }
+    }
+
     std::vector<unsigned int> collect_sorted_used_filaments(const std::vector<std::vector<unsigned int>>& layer_filaments)
     {
         std::set<unsigned int>used_filaments_set;
@@ -217,7 +373,7 @@ namespace Slic3r
 
     void KMediods2::do_clustering(const FGStrategy& g_strategy, int timeout_ms)
     {
-        FlushTimeMachine T;
+        FilamentGroupUtils::FlushTimeMachine T;
         T.time_machine_start();
 
         if (m_elem_count < m_k) {
@@ -245,6 +401,15 @@ namespace Slic3r
                     best_cost = new_cost;
                     best_labels = new_labels;
                 }
+
+                {
+                    MemoryedGroup g;
+                    g.prefer_level = 1; // in non enum mode, we use the same prefer level
+                    g.cost = new_cost;
+                    g.group = new_labels;
+                    update_memoryed_groups(g, memory_threshold, memoryed_groups);
+                }
+
                 if (T.time_machine_end() > timeout_ms)
                     break;
             }
@@ -281,6 +446,9 @@ namespace Slic3r
         static constexpr int UNPLACEABLE_LIMIT_REWARD = 100;  // reward value if the group result follows the unprintable limit
         static constexpr int MAX_SIZE_LIMIT_REWARD = 10;    // reward value if the group result follows the max size per extruder
         static constexpr int BEST_FIT_LIMIT_REWARD = 1;     // reward value if the group result try to fill the max size per extruder
+
+        MemoryedGroupHeap memoryed_groups;
+
         auto bit_count_one = [](uint64_t n)
             {
                 int count = 0;
@@ -360,15 +528,26 @@ namespace Slic3r
                 best_cost = total_cost;
                 best_label = filament_maps;
             }
+
+            {
+                MemoryedGroup mg;
+                mg.prefer_level = prefer_level;
+                mg.cost = total_cost;
+                mg.group = std::move(filament_maps);
+                update_memoryed_groups(mg, memory_threshold, memoryed_groups);
+            }
         }
 
         if (cost)
             *cost = best_cost;
 
         std::vector<int> filament_labels(m_context.total_filament_num, 0);
-        for (int i = 0; i < best_label.size(); ++i)
+        for (size_t i = 0; i < best_label.size(); ++i)
             filament_labels[used_filaments[i]] = best_label[i];
 
+
+        change_memoryed_heaps_to_arrays(memoryed_groups, m_context.total_filament_num, used_filaments, m_memoryed_groups);
+
         return filament_labels;
     }
 
@@ -400,9 +579,16 @@ namespace Slic3r
         KMediods2 PAM((int)used_filaments.size(),distance_evaluator);
         PAM.set_max_cluster_size(m_context.max_group_size);
         PAM.set_unplaceable_limits(unplaceable_limits);
+        PAM.set_memory_threshold(memory_threshold);
         PAM.do_clustering(g_strategy, timeout_ms);
         std::vector<int>filament_labels = PAM.get_cluster_labels();
 
+
+        {
+            auto memoryed_groups = PAM.get_memoryed_groups();
+            change_memoryed_heaps_to_arrays(memoryed_groups, m_context.total_filament_num, used_filaments, m_memoryed_groups);
+        }
+
         if(cost)
             *cost=reorder_filaments_for_minimum_flush_volume(used_filaments,filament_labels,layer_filaments,m_context.flush_matrix,std::nullopt,nullptr);
 
diff --git a/src/libslic3r/FilamentGroup.hpp b/src/libslic3r/FilamentGroup.hpp
index ca2088e79..0d20b8064 100644
--- a/src/libslic3r/FilamentGroup.hpp
+++ b/src/libslic3r/FilamentGroup.hpp
@@ -7,38 +7,68 @@
 #include <set>
 #include <map>
 #include <vector>
+#include <queue>
 #include "GCode/ToolOrderUtils.hpp"
 
 const static int DEFAULT_CLUSTER_SIZE = 16;
 
+const static int ABSOLUTE_FLUSH_GAP_TOLERANCE = 2000;
+
 namespace Slic3r
 {
     std::vector<unsigned int>collect_sorted_used_filaments(const std::vector<std::vector<unsigned int>>& layer_filaments);
 
-    struct FlushTimeMachine
-    {
-    private:
-        std::chrono::high_resolution_clock::time_point start;
-
-    public:
-        void time_machine_start()
-        {
-            start = std::chrono::high_resolution_clock::now();
-        }
-
-        int time_machine_end()
-        {
-            auto end = std::chrono::high_resolution_clock::now();
-            auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
-            return duration.count();
-        }
-    };
-
     enum FGStrategy {
         BestCost,
         BestFit
     };
 
+    struct Color
+    {
+        unsigned char r = 0;
+        unsigned char g = 0;
+        unsigned char b = 0;
+        unsigned char a = 255;
+        Color(unsigned char r_ = 0, unsigned char g_ = 0, unsigned char b_ = 0, unsigned a_ = 255) :r(r_), g(g_), b(b_), a(a_) {}
+        Color(const std::string& hexstr);
+    };
+
+    std::vector<int> select_best_group_for_ams(const std::vector<std::vector<int>>& map_lists, const std::vector<unsigned int>& used_filaments, const std::vector<std::string>& used_filament_colors, const std::vector<std::vector<std::string>>& ams_filament_colros);
+
+    namespace FilamentGroupUtils
+    {
+        struct FlushTimeMachine
+        {
+        private:
+            std::chrono::high_resolution_clock::time_point start;
+
+        public:
+            void time_machine_start()
+            {
+                start = std::chrono::high_resolution_clock::now();
+            }
+
+            int time_machine_end()
+            {
+                auto end = std::chrono::high_resolution_clock::now();
+                auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(end - start);
+                return duration.count();
+            }
+        };
+
+        struct MemoryedGroup {
+            int cost{ 0 };
+            int prefer_level{ 0 };
+            std::vector<int>group;
+            bool operator>(const MemoryedGroup& other) const {
+                return prefer_level < other.prefer_level || (prefer_level == other.prefer_level && cost > other.cost);
+            }
+        };
+        using MemoryedGroupHeap = std::priority_queue<MemoryedGroup, std::vector<MemoryedGroup>, std::greater<MemoryedGroup>>;
+
+        void update_memoryed_groups(const MemoryedGroup& item,const double gap_threshold, MemoryedGroupHeap& groups);
+    }
+
     struct FilamentGroupContext
     {
         std::vector<FlushMatrix> flush_matrix;
@@ -62,14 +92,21 @@ namespace Slic3r
 
     class FilamentGroup
     {
+        using MemoryedGroupHeap = FilamentGroupUtils::MemoryedGroupHeap;
+        using MemoryedGroup = FilamentGroupUtils::MemoryedGroup;
     public:
         FilamentGroup(const FilamentGroupContext& context);
         std::vector<int> calc_filament_group(const std::vector<std::vector<unsigned int>>& layer_filaments, const FGStrategy& g_strategy = FGStrategy::BestFit, int* cost = nullptr);
     public:
         std::vector<int> calc_filament_group_by_enum(const std::vector<std::vector<unsigned int>>& layer_filaments, const std::vector<unsigned int>& used_filaments, const FGStrategy& g_strategy, int* cost = nullptr);
         std::vector<int> calc_filament_group_by_pam2(const std::vector<std::vector<unsigned int>>& layer_filaments, const std::vector<unsigned int>& used_filaments, const FGStrategy& g_strategy, int* cost = nullptr, int timeout_ms = 300);
+        void set_memory_threshold(double threshold) { memory_threshold = threshold; }
+        std::vector<std::vector<int>> get_memoryed_groups()const { return m_memoryed_groups; }
     private:
         FilamentGroupContext m_context;
+        double memory_threshold{ 0 };
+        std::vector<std::vector<int>> m_memoryed_groups;
+
     public:
         std::optional<std::function<bool(int, std::vector<int>&)>> get_custom_seq;
     };
@@ -77,6 +114,9 @@ namespace Slic3r
 
     class KMediods2
     {
+        using MemoryedGroupHeap = FilamentGroupUtils::MemoryedGroupHeap;
+        using MemoryedGroup = FilamentGroupUtils::MemoryedGroup;
+
         enum INIT_TYPE
         {
             Random = 0,
@@ -97,6 +137,10 @@ namespace Slic3r
         void set_unplaceable_limits(const std::map<int, int>& placeable_limits) { m_unplaceable_limits = placeable_limits; }
 
         void do_clustering(const FGStrategy& g_strategy,int timeout_ms = 100);
+
+        void set_memory_threshold(double threshold) { memory_threshold; }
+        MemoryedGroupHeap get_memoryed_groups()const { return memoryed_groups; }
+
         std::vector<int>get_cluster_labels()const { return m_cluster_labels; }
 
     private:
@@ -110,6 +154,9 @@ namespace Slic3r
         int m_elem_count;
         const int m_k = 2;
 
+        double memory_threshold{ 0 };
+        FilamentGroupUtils::MemoryedGroupHeap memoryed_groups;
+
         std::vector<int>m_cluster_labels;
     };
 }
diff --git a/src/libslic3r/GCode/ToolOrdering.cpp b/src/libslic3r/GCode/ToolOrdering.cpp
index cad3ba67a..d568b7995 100644
--- a/src/libslic3r/GCode/ToolOrdering.cpp
+++ b/src/libslic3r/GCode/ToolOrdering.cpp
@@ -889,7 +889,7 @@ float get_flush_volume(const std::vector<int> &filament_maps, const std::vector<
     return flush_volume;
 }
 
-std::vector<int> ToolOrdering::get_recommended_filament_maps(const std::vector<std::vector<unsigned int>>& layer_filaments, const PrintConfig* print_config, const std::vector<std::set<int>>&physical_unprintables,const std::vector<std::set<int>>&geometric_unprintables)
+std::vector<int> ToolOrdering::get_recommended_filament_maps(const std::vector<std::vector<unsigned int>>& layer_filaments, const PrintConfig* print_config, const Print* print, const std::vector<std::set<int>>&physical_unprintables,const std::vector<std::set<int>>&geometric_unprintables)
 {
     if (!print_config || layer_filaments.empty())
         return std::vector<int>();
@@ -967,8 +967,25 @@ std::vector<int> ToolOrdering::get_recommended_filament_maps(const std::vector<s
         }
         else {
             FilamentGroup fg(context);
+            fg.set_memory_threshold(0.02);
             fg.get_custom_seq = get_custom_seq;
+
             ret = fg.calc_filament_group(layer_filaments, FGStrategy::BestFit);
+            auto memoryed_maps = fg.get_memoryed_groups();
+
+            std::vector<std::string>used_colors;
+            for (size_t idx = 0; idx < used_filaments.size(); ++idx)
+                used_colors.emplace_back(print_config->filament_colour.get_at(used_filaments[idx]));
+
+            auto ams_filament_info = print->get_extruder_filament_info();
+            std::vector<std::vector<std::string>> ams_colors;
+            for (auto& arr : ams_filament_info) {
+                std::vector<std::string>colors;
+                for (auto& item : arr)
+                    colors.emplace_back(item.option<ConfigOptionStrings>("filament_colour")->get_at(0));
+                ams_colors.emplace_back(std::move(colors));
+            }
+            ret = select_best_group_for_ams(memoryed_maps, used_filaments, used_colors, ams_colors);
         }
     }
 
@@ -1040,7 +1057,7 @@ void ToolOrdering::reorder_extruders_for_minimum_flush_volume(bool reorder_first
                     print_config = &(m_print_object_ptr->print()->config());
                 }
 
-                filament_maps = ToolOrdering::get_recommended_filament_maps(layer_filaments, print_config, physical_unprintables, geometric_unprintables);
+                filament_maps = ToolOrdering::get_recommended_filament_maps(layer_filaments, print_config, m_print, physical_unprintables, geometric_unprintables);
 
                 if (filament_maps.empty())
                     return;
@@ -1138,7 +1155,7 @@ void ToolOrdering::reorder_extruders_for_minimum_flush_volume(bool reorder_first
         if (map_mode == fmmManual)
         {
             std::vector<std::vector<unsigned int>>filament_sequences_one_extruder;
-            std::vector<int>filament_maps_auto = get_recommended_filament_maps(layer_filaments, print_config, physical_unprintables, geometric_unprintables);
+            std::vector<int>filament_maps_auto = get_recommended_filament_maps(layer_filaments, print_config, m_print, physical_unprintables, geometric_unprintables);
             reorder_filaments_for_minimum_flush_volume(
                 filament_lists,
                 filament_maps_auto,
diff --git a/src/libslic3r/GCode/ToolOrdering.hpp b/src/libslic3r/GCode/ToolOrdering.hpp
index 903fa5891..76364ef3d 100644
--- a/src/libslic3r/GCode/ToolOrdering.hpp
+++ b/src/libslic3r/GCode/ToolOrdering.hpp
@@ -234,7 +234,7 @@ public:
     * called in dual extruder mode, the value in map will be 0 or 1
     * 0 based group id
     */
-    static std::vector<int> get_recommended_filament_maps(const std::vector<std::vector<unsigned int>>& layer_filaments, const PrintConfig* print_config, const std::vector<std::set<int>>& physical_unprintables, const std::vector<std::set<int>>& geometric_unprintables);
+    static std::vector<int> get_recommended_filament_maps(const std::vector<std::vector<unsigned int>>& layer_filaments, const PrintConfig* print_config, const Print* print, const std::vector<std::set<int>>& physical_unprintables, const std::vector<std::set<int>>& geometric_unprintables);
 
     static std::vector<std::set<int>> get_physical_unprintables(const std::vector<unsigned int>& layer_filaments, const PrintConfig* config, int master_extruder_id = 1);
     static std::vector<std::set<int>> get_geometrical_unprintables(const std::vector<std::vector<int>>& unprintable_arrs, const PrintConfig* config);
diff --git a/src/libslic3r/Print.cpp b/src/libslic3r/Print.cpp
index e3208e963..af4718956 100644
--- a/src/libslic3r/Print.cpp
+++ b/src/libslic3r/Print.cpp
@@ -1879,7 +1879,7 @@ void Print::process(std::unordered_map<std::string, long long>* slice_time, bool
                 auto map_mode = get_filament_map_mode();
                 // get recommended filament map
                 if (map_mode == FilamentMapMode::fmmAuto) {
-                    filament_maps = ToolOrdering::get_recommended_filament_maps(all_filaments, &config(), physical_unprintables, geometric_unprintables);
+                    filament_maps = ToolOrdering::get_recommended_filament_maps(all_filaments, &config(), this, physical_unprintables, geometric_unprintables);
                     std::transform(filament_maps.begin(), filament_maps.end(), filament_maps.begin(), [](int value) { return value + 1; });
                     update_filament_maps_to_config(filament_maps);
                 }