--- ../src-base/minecraft/net/minecraft/client/renderer/color/ItemColors.java
+++ ../src-work/minecraft/net/minecraft/client/renderer/color/ItemColors.java
@@ -26,7 +26,8 @@
 @SideOnly(Side.CLIENT)
 public class ItemColors
 {
-    private final ObjectIntIdentityMap<IItemColor> field_186732_a = new ObjectIntIdentityMap<IItemColor>(32);
+    // FORGE: Use RegistryDelegates as non-Vanilla item ids are not constant
+    private final java.util.Map<net.minecraftforge.registries.IRegistryDelegate<Item>, IItemColor> itemColorMap = com.google.common.collect.Maps.newHashMap();
 
     public static ItemColors func_186729_a(final BlockColors p_186729_0_)
     {
@@ -137,12 +138,13 @@
                 return p_186726_2_ == 0 ? -1 : ItemMap.func_190907_h(p_186726_1_);
             }
         }, Items.field_151098_aY);
+        net.minecraftforge.client.ForgeHooksClient.onItemColorsInit(itemcolors, p_186729_0_);
         return itemcolors;
     }
 
     public int func_186728_a(ItemStack p_186728_1_, int p_186728_2_)
     {
-        IItemColor iitemcolor = this.field_186732_a.func_148745_a(Item.field_150901_e.func_148757_b(p_186728_1_.func_77973_b()));
+        IItemColor iitemcolor = this.itemColorMap.get(p_186728_1_.func_77973_b().delegate);
         return iitemcolor == null ? -1 : iitemcolor.func_186726_a(p_186728_1_, p_186728_2_);
     }
 
@@ -150,7 +152,9 @@
     {
         for (Block block : p_186731_2_)
         {
-            this.field_186732_a.func_148746_a(p_186731_1_, Item.func_150891_b(Item.func_150898_a(block)));
+            if (block == null) throw new IllegalArgumentException("Block registered to item color handler cannot be null!");
+            if (block.getRegistryName() == null) throw new IllegalArgumentException("Block must be registered before assigning color handler.");
+            this.itemColorMap.put(Item.func_150898_a(block).delegate, p_186731_1_);
         }
     }
 
@@ -158,7 +162,9 @@
     {
         for (Item item : p_186730_2_)
         {
-            this.field_186732_a.func_148746_a(p_186730_1_, Item.func_150891_b(item));
+            if (item == null) throw new IllegalArgumentException("Item registered to item color handler cannot be null!");
+            if (item.getRegistryName() == null) throw new IllegalArgumentException("Item must be registered before assigning color handler.");
+            this.itemColorMap.put(item.delegate, p_186730_1_);
         }
     }
 }