Allow AreaEffectCloud#setColor to reset color for null (#12760)

Author: NonSwag

paper-api/src/main/java/org/bukkit/entity/AreaEffectCloud.java

@@ -241,9 +241,9 @@ public interface AreaEffectCloud extends Entity {
     /**
      * Sets the color of this cloud. Will be applied as a tint to its particles.
      *
-     * @param color cloud color
+     * @param color cloud color or {@code null} to reset to default
      */
-    void setColor(@NotNull Color color);
+    void setColor(@Nullable Color color);
 
     /**
      * Retrieve the original source of this cloud.

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftAreaEffectCloud.java

@@ -128,7 +128,7 @@ public Color getColor() {
     @Override
     public void setColor(Color color) {
         PotionContents old = this.getHandle().potionContents;
-        this.getHandle().setPotionContents(new PotionContents(old.potion(), Optional.of(color.asRGB()), old.customEffects(), old.customName()));
+        this.getHandle().setPotionContents(new PotionContents(old.potion(), Optional.ofNullable(color).map(Color::asRGB), old.customEffects(), old.customName()));
     }
 
     @Override