diff --git a/src/client/Client.cpp b/src/client/Client.cpp
index 2182b1e66..1e2d8531d 100644
--- a/src/client/Client.cpp
+++ b/src/client/Client.cpp
@@ -511,34 +511,6 @@ void Client::SaveAuthorInfo(Json::Value *saveInto)
 	}
 }
 
-bool AddCustomGol(String ruleString, String nameString, unsigned int highColor, unsigned int lowColor)
-{
-	auto &prefs = GlobalPrefs::Ref();
-	auto customGOLTypes = prefs.Get("CustomGOL.Types", std::vector<ByteString>{});
-	std::vector<ByteString> newCustomGOLTypes;
-	bool nameTaken = false;
-	for (auto gol : customGOLTypes)
-	{
-		auto parts = gol.FromUtf8().PartitionBy(' ');
-		if (parts.size())
-		{
-			if (parts[0] == nameString)
-			{
-				nameTaken = true;
-			}
-		}
-		newCustomGOLTypes.push_back(gol);
-	}
-	if (nameTaken)
-		return false;
-
-	StringBuilder sb;
-	sb << nameString << " " << ruleString << " " << highColor << " " << lowColor;
-	newCustomGOLTypes.push_back(sb.Build().ToUtf8());
-	prefs.Set("CustomGOL.Types", newCustomGOLTypes);
-	return true;
-}
-
 String Client::DoMigration(ByteString fromDir, ByteString toDir)
 {
 	if (fromDir.at(fromDir.length() - 1) != '/')
diff --git a/src/client/Client.h b/src/client/Client.h
index 365dfa51e..c3beb6f7b 100644
--- a/src/client/Client.h
+++ b/src/client/Client.h
@@ -105,5 +105,3 @@ public:
 	
 	String DoMigration(ByteString fromDir, ByteString toDir);
 };
-
-bool AddCustomGol(String ruleString, String nameString, unsigned int highColor, unsigned int lowColor);
diff --git a/src/graphics/Pixel.h b/src/graphics/Pixel.h
index 43b90b4b6..5e6c2545f 100644
--- a/src/graphics/Pixel.h
+++ b/src/graphics/Pixel.h
@@ -24,6 +24,8 @@ struct alignas(alignof(uint32_t) > alignof(T) ? alignof(uint32_t) : alignof(T))
 {
 	T Blue, Green, Red;
 
+	constexpr RGB() = default;
+
 	constexpr RGB(T r, T g, T b):
 		Blue(b),
 		Green(g),
@@ -121,6 +123,8 @@ struct alignas(alignof(uint32_t) > alignof(T) ? alignof(uint32_t) : alignof(T))
 {
 	T Blue, Green, Red, Alpha;
 
+	constexpr RGBA() = default;
+
 	constexpr RGBA(T r, T g, T b, T a):
 		Blue(b),
 		Green(g),
diff --git a/src/gui/game/GameController.cpp b/src/gui/game/GameController.cpp
index ac0a0834c..1037ee21f 100644
--- a/src/gui/game/GameController.cpp
+++ b/src/gui/game/GameController.cpp
@@ -1719,9 +1719,9 @@ bool GameController::GetMouseClickRequired()
 	return gameModel->GetMouseClickRequired();
 }
 
-void GameController::RemoveCustomGOLType(const ByteString &identifier)
+void GameController::RemoveCustomGol(const ByteString &identifier)
 {
-	gameModel->RemoveCustomGOLType(identifier);
+	gameModel->RemoveCustomGol(identifier);
 }
 
 void GameController::BeforeSimDraw()
diff --git a/src/gui/game/GameController.h b/src/gui/game/GameController.h
index fb605d9bb..b3f0ded37 100644
--- a/src/gui/game/GameController.h
+++ b/src/gui/game/GameController.h
@@ -201,7 +201,7 @@ public:
 	void RunUpdater(UpdateInfo info);
 	bool GetMouseClickRequired();
 
-	void RemoveCustomGOLType(const ByteString &identifier);
+	void RemoveCustomGol(const ByteString &identifier);
 
 	void BeforeSimDraw();
 	void AfterSimDraw();
diff --git a/src/gui/game/GameModel.cpp b/src/gui/game/GameModel.cpp
index 70d6399e2..a2f6f1323 100644
--- a/src/gui/game/GameModel.cpp
+++ b/src/gui/game/GameModel.cpp
@@ -137,6 +137,7 @@ GameModel::GameModel():
 		currentUser = Client::Ref().GetAuthUser();
 	}
 
+	LoadCustomGol();
 	BuildMenus();
 
 	perfectCircle = prefs.Get("PerfectCircleBrush", true);
@@ -312,60 +313,10 @@ void GameModel::BuildMenus()
 		Tool * tempTool = AddTool<ElementTool>(PT_LIFE|PMAPID(i), builtinGol[i].name, builtinGol[i].description, builtinGol[i].colour, "DEFAULT_PT_LIFE_"+builtinGol[i].name.ToAscii());
 		menuList[SC_LIFE]->AddTool(tempTool);
 	}
+	for (auto &gd : sd.GetCustomGol())
 	{
-		auto &prefs = GlobalPrefs::Ref();
-		auto customGOLTypes = prefs.Get("CustomGOL.Types", std::vector<ByteString>{});
-		std::vector<ByteString> validatedCustomLifeTypes;
-		std::vector<CustomGOLData> newCustomGol;
-		bool removedAny = false;
-		for (auto gol : customGOLTypes)
-		{
-			auto parts = gol.FromUtf8().PartitionBy(' ');
-			if (parts.size() != 4)
-			{
-				removedAny = true;
-				continue;
-			}
-			CustomGOLData gd;
-			gd.nameString = parts[0];
-			gd.ruleString = parts[1];
-			auto &colour1String = parts[2];
-			auto &colour2String = parts[3];
-			if (!ValidateGOLName(gd.nameString))
-			{
-				removedAny = true;
-				continue;
-			}
-			gd.rule = ParseGOLString(gd.ruleString);
-			if (gd.rule == -1)
-			{
-				removedAny = true;
-				continue;
-			}
-			try
-			{
-				gd.colour1 = colour1String.ToNumber<int>();
-				gd.colour2 = colour2String.ToNumber<int>();
-			}
-			catch (std::exception &)
-			{
-				removedAny = true;
-				continue;
-			}
-			newCustomGol.push_back(gd);
-			validatedCustomLifeTypes.push_back(gol);
-		}
-		if (removedAny)
-		{
-			// All custom rules that fail validation will be removed
-			prefs.Set("CustomGOL.Types", validatedCustomLifeTypes);
-		}
-		for (auto &gd : newCustomGol)
-		{
-			Tool * tempTool = AddTool<ElementTool>(PT_LIFE|PMAPID(gd.rule), gd.nameString, "Custom GOL type: " + gd.ruleString, RGB<uint8_t>::Unpack(gd.colour1), "DEFAULT_PT_LIFECUST_"+gd.nameString.ToAscii(), nullptr);
-			menuList[SC_LIFE]->AddTool(tempTool);
-		}
-		sd.SetCustomGOL(newCustomGol);
+		Tool * tempTool = AddTool<ElementTool>(PT_LIFE|PMAPID(gd.rule), gd.nameString, "Custom GOL type: " + SerialiseGOLRule(gd.rule), gd.colour1, "DEFAULT_PT_LIFECUST_"+gd.nameString.ToAscii(), nullptr);
+		menuList[SC_LIFE]->AddTool(tempTool);
 	}
 
 	//Build other menus from wall data
@@ -1664,28 +1615,129 @@ void GameModel::SetPerfectCircle(bool perfectCircle)
 	}
 }
 
-bool GameModel::RemoveCustomGOLType(const ByteString &identifier)
+bool GameModel::AddCustomGol(String ruleString, String nameString, RGB<uint8_t> color1, RGB<uint8_t> color2)
+{
+	if (auto gd = CheckCustomGol(ruleString, nameString, color1, color2))
+	{
+		auto &sd = SimulationData::Ref();
+		auto newCustomGol = sd.GetCustomGol();
+		newCustomGol.push_back(*gd);
+		sd.SetCustomGOL(newCustomGol);
+		SaveCustomGol();
+		BuildMenus();
+		return true;
+	}
+	return false;
+}
+
+bool GameModel::RemoveCustomGol(const ByteString &identifier)
 {
 	bool removedAny = false;
-	auto &prefs = GlobalPrefs::Ref();
-	auto customGOLTypes = prefs.Get("CustomGOL.Types", std::vector<ByteString>{});
-	std::vector<ByteString> newCustomGOLTypes;
-	for (auto gol : customGOLTypes)
+	std::vector<CustomGOLData> newCustomGol;
+	auto &sd = SimulationData::Ref();
+	for (auto gol : sd.GetCustomGol())
 	{
-		auto parts = gol.PartitionBy(' ');
-		if (parts.size() && "DEFAULT_PT_LIFECUST_" + parts[0] == identifier)
+		if ("DEFAULT_PT_LIFECUST_" + gol.nameString == identifier.FromUtf8())
+		{
 			removedAny = true;
+		}
 		else
-			newCustomGOLTypes.push_back(gol);
+		{
+			newCustomGol.push_back(gol);
+		}
 	}
 	if (removedAny)
 	{
-		prefs.Set("CustomGOL.Types", newCustomGOLTypes);
+		sd.SetCustomGOL(newCustomGol);
+		BuildMenus();
+		SaveCustomGol();
 	}
-	BuildMenus();
 	return removedAny;
 }
 
+void GameModel::LoadCustomGol()
+{
+	auto &prefs = GlobalPrefs::Ref();
+	auto customGOLTypes = prefs.Get("CustomGOL.Types", std::vector<ByteString>{});
+	bool removedAny = false;
+	std::vector<CustomGOLData> newCustomGol;
+	for (auto gol : customGOLTypes)
+	{
+		auto parts = gol.FromUtf8().PartitionBy(' ');
+		if (parts.size() != 4)
+		{
+			removedAny = true;
+			continue;
+		}
+		auto nameString = parts[0];
+		auto ruleString = parts[1];
+		auto &colour1String = parts[2];
+		auto &colour2String = parts[3];
+		RGB<uint8_t> color1;
+		RGB<uint8_t> color2;
+		try
+		{
+			color1 = RGB<uint8_t>::Unpack(colour1String.ToNumber<int>());
+			color2 = RGB<uint8_t>::Unpack(colour2String.ToNumber<int>());
+		}
+		catch (std::exception &)
+		{
+			removedAny = true;
+			continue;
+		}
+		if (auto gd = CheckCustomGol(ruleString, nameString, color1, color2))
+		{
+			newCustomGol.push_back(*gd);
+		}
+		else
+		{
+			removedAny = true;
+		}
+	}
+	auto &sd = SimulationData::Ref();
+	sd.SetCustomGOL(newCustomGol);
+	if (removedAny)
+	{
+		SaveCustomGol();
+	}
+}
+
+void GameModel::SaveCustomGol()
+{
+	auto &prefs = GlobalPrefs::Ref();
+	std::vector<ByteString> newCustomGOLTypes;
+	auto &sd = SimulationData::Ref();
+	for (auto &gd : sd.GetCustomGol())
+	{
+		StringBuilder sb;
+		sb << gd.nameString << " " << SerialiseGOLRule(gd.rule) << " " << gd.colour1.Pack() << " " << gd.colour2.Pack();
+		newCustomGOLTypes.push_back(sb.Build().ToUtf8());
+	}
+	prefs.Set("CustomGOL.Types", newCustomGOLTypes);
+}
+
+std::optional<CustomGOLData> GameModel::CheckCustomGol(String ruleString, String nameString, RGB<uint8_t> color1, RGB<uint8_t> color2)
+{
+	if (!ValidateGOLName(nameString))
+	{
+		return std::nullopt;
+	}
+	auto rule = ParseGOLString(ruleString);
+	if (rule == -1)
+	{
+		return std::nullopt;
+	}
+	auto &sd = SimulationData::Ref();
+	for (auto &gd : sd.GetCustomGol())
+	{
+		if (gd.nameString == nameString)
+		{
+			return std::nullopt;
+		}
+	}
+	return CustomGOLData{ rule, color1, color2, nameString };
+}
+
 void GameModel::UpdateUpTo(int upTo)
 {
 	if (upTo < sim->debug_nextToUpdate)
diff --git a/src/gui/game/GameModel.h b/src/gui/game/GameModel.h
index 2bd82ff31..6f9cfe8c7 100644
--- a/src/gui/game/GameModel.h
+++ b/src/gui/game/GameModel.h
@@ -3,6 +3,7 @@
 #include "client/User.h"
 #include "gui/interface/Point.h"
 #include "graphics/RendererSettings.h"
+#include "simulation/CustomGOLData.h"
 #include <vector>
 #include <deque>
 #include <memory>
@@ -295,7 +296,11 @@ public:
 	void AddNotification(Notification * notification);
 	void RemoveNotification(Notification * notification);
 
-	bool RemoveCustomGOLType(const ByteString &identifier);
+	bool AddCustomGol(String ruleString, String nameString, RGB<uint8_t> color1, RGB<uint8_t> color2);
+	bool RemoveCustomGol(const ByteString &identifier);
+	void LoadCustomGol();
+	void SaveCustomGol();
+	std::optional<CustomGOLData> CheckCustomGol(String ruleString, String nameString, RGB<uint8_t> color1, RGB<uint8_t> color2);
 
 	ByteString SelectNextIdentifier;
 	int SelectNextTool;
diff --git a/src/gui/game/GameView.cpp b/src/gui/game/GameView.cpp
index 06f923d21..eda9c67a2 100644
--- a/src/gui/game/GameView.cpp
+++ b/src/gui/game/GameView.cpp
@@ -602,7 +602,7 @@ void GameView::NotifyToolListChanged(GameModel * sender)
 					else if (identifier.BeginsWith("DEFAULT_PT_LIFECUST_"))
 					{
 						new ConfirmPrompt("Remove custom GOL type", "Are you sure you want to remove " + identifier.Substr(20).FromUtf8() + "?", { [this, identifier]() {
-							c->RemoveCustomGOLType(identifier);
+							c->RemoveCustomGol(identifier);
 						} });
 					}
 				}
diff --git a/src/gui/game/tool/GOLTool.cpp b/src/gui/game/tool/GOLTool.cpp
index 1bfd5ff26..467a5dc81 100644
--- a/src/gui/game/tool/GOLTool.cpp
+++ b/src/gui/game/tool/GOLTool.cpp
@@ -159,9 +159,7 @@ void GOLWindow::validate()
 		prefs.Set("CustomGOL.Rule", ruleString);
 	}
 
-	auto color1 = (((highColour.Red << 8) | highColour.Green) << 8) | highColour.Blue;
-	auto color2 = (((lowColour.Red << 8) | lowColour.Green) << 8) | lowColour.Blue;
-	if (!AddCustomGol(ruleString, nameString, color1, color2))
+	if (!gameModel.AddCustomGol(ruleString, nameString, highColour.NoAlpha(), lowColour.NoAlpha()))
 	{
 		new ErrorMessage("Could not add GOL type", "Name already taken");
 		return;
diff --git a/src/lua/LuaSimulation.cpp b/src/lua/LuaSimulation.cpp
index 6dd6e55c2..d2371d94a 100644
--- a/src/lua/LuaSimulation.cpp
+++ b/src/lua/LuaSimulation.cpp
@@ -1489,13 +1489,13 @@ static int listCustomGol(lua_State *L)
 		lua_newtable(L);
 		tpt_lua_pushString(L, cgol.nameString);
 		lua_setfield(L, -2, "name");
-		tpt_lua_pushString(L, cgol.ruleString);
+		tpt_lua_pushString(L, SerialiseGOLRule(cgol.rule));
 		lua_setfield(L, -2, "rulestr");
 		lua_pushnumber(L, cgol.rule);
 		lua_setfield(L, -2, "rule");
-		lua_pushnumber(L, cgol.colour1);
+		lua_pushnumber(L, cgol.colour1.Pack());
 		lua_setfield(L, -2, "color1");
-		lua_pushnumber(L, cgol.colour2);
+		lua_pushnumber(L, cgol.colour2.Pack());
 		lua_setfield(L, -2, "color2");
 		lua_rawseti(L, -2, ++i);
 	}
@@ -1529,10 +1529,9 @@ static int addCustomGol(lua_State *L)
 	if (sd.GetCustomGOLByRule(rule))
 		return luaL_error(L, "This Custom GoL rule already exists");
 
-	if (!AddCustomGol(ruleString, nameString, color1, color2))
-		return luaL_error(L, "Duplicate name, cannot add");
 	auto *lsi = GetLSI();
-	lsi->gameModel->BuildMenus();
+	if (!lsi->gameModel->AddCustomGol(ruleString, nameString, RGB<uint8_t>::Unpack(color1), RGB<uint8_t>::Unpack(color2)))
+		return luaL_error(L, "Duplicate name, cannot add");
 	return 0;
 }
 
@@ -1540,9 +1539,7 @@ static int removeCustomGol(lua_State *L)
 {
 	auto *lsi = GetLSI();
 	ByteString nameString = tpt_lua_checkByteString(L, 1);
-	bool removedAny = lsi->gameModel->RemoveCustomGOLType("DEFAULT_PT_LIFECUST_" + nameString);
-	if (removedAny)
-		lsi->gameModel->BuildMenus();
+	bool removedAny = lsi->gameModel->RemoveCustomGol("DEFAULT_PT_LIFECUST_" + nameString);
 	lua_pushboolean(L, removedAny);
 	return 1;
 }
diff --git a/src/simulation/CustomGOLData.h b/src/simulation/CustomGOLData.h
new file mode 100644
index 000000000..50f951bcb
--- /dev/null
+++ b/src/simulation/CustomGOLData.h
@@ -0,0 +1,15 @@
+#pragma once
+#include "graphics/Pixel.h"
+#include "common/String.h"
+
+struct CustomGOLData
+{
+	int rule;
+	RGB<uint8_t> colour1, colour2;
+	String nameString;
+
+	inline bool operator <(const CustomGOLData &other) const
+	{
+		return rule < other.rule;
+	}
+};
diff --git a/src/simulation/SimulationData.h b/src/simulation/SimulationData.h
index 0490b081e..3e9f0129a 100644
--- a/src/simulation/SimulationData.h
+++ b/src/simulation/SimulationData.h
@@ -9,6 +9,7 @@
 #include "Particle.h"
 #include "WallType.h"
 #include "graphics/gcache_item.h"
+#include "CustomGOLData.h"
 #include <cstdint>
 #include <vector>
 #include <array>
@@ -140,17 +141,6 @@ constexpr int NGT_BRAN = 23;
 constexpr auto REPLACE_MODE    = UINT32_C(0x00000001);
 constexpr auto SPECIFIC_DELETE = UINT32_C(0x00000002);
 
-struct CustomGOLData
-{
-	int rule, colour1, colour2;
-	String nameString, ruleString;
-
-	inline bool operator <(const CustomGOLData &other) const
-	{
-		return rule < other.rule;
-	}
-};
-
 class SimulationData : public ExplicitSingleton<SimulationData>
 {
 public:
diff --git a/src/simulation/elements/LIFE.cpp b/src/simulation/elements/LIFE.cpp
index a0fb1058f..67563f470 100644
--- a/src/simulation/elements/LIFE.cpp
+++ b/src/simulation/elements/LIFE.cpp
@@ -111,8 +111,8 @@ static void create(ELEMENT_CREATE_FUNC_ARGS)
 		auto *cgol = sd.GetCustomGOLByRule(v);
 		if (cgol)
 		{
-			sim->parts[i].dcolour = cgol->colour1;
-			sim->parts[i].tmp = cgol->colour2;
+			sim->parts[i].dcolour = cgol->colour1.Pack();
+			sim->parts[i].tmp = cgol->colour2.Pack();
 		}
 	}
 	sim->parts[i].tmp2 = ((v >> 17) & 0xF) + 1;