Paper/nms-patches/ItemDye.patch

--- a/net/minecraft/server/ItemDye.java
+++ b/net/minecraft/server/ItemDye.java
@@ -1,5 +1,7 @@
 package net.minecraft.server;
 
+import org.bukkit.event.entity.SheepDyeWoolEvent; // CraftBukkit
+
 public class ItemDye extends Item {
 
     public static final int[] a = new int[] { 1973019, 11743532, 3887386, 5320730, 2437522, 8073150, 2651799, 11250603, 4408131, 14188952, 4312372, 14602026, 6719955, 12801229, 15435844, 15790320};
@@ -87,6 +89,17 @@
             EnumColor enumcolor = EnumColor.fromInvColorIndex(itemstack.getData());
 
             if (!entitysheep.isSheared() && entitysheep.getColor() != enumcolor) {
+                // CraftBukkit start
+                byte bColor = (byte) enumcolor.getColorIndex();
+                SheepDyeWoolEvent event = new SheepDyeWoolEvent((org.bukkit.entity.Sheep) entitysheep.getBukkitEntity(), org.bukkit.DyeColor.getByData(bColor));
+                entitysheep.world.getServer().getPluginManager().callEvent(event);
+
+                if (event.isCancelled()) {
+                    return false;
+                }
+
+                enumcolor = EnumColor.fromColorIndex((byte) event.getColor().getWoolData());
+                // CraftBukkit end
                 entitysheep.setColor(enumcolor);
                 --itemstack.count;
             }