[DSL] Expose ColorUtil methods to DSL rules (#3879)

New functions for RGBW introduced in #3849.

Signed-off-by: Holger Friedrich <mail@holger-friedrich.de>

bundles/org.openhab.core.model.script/src/org/openhab/core/model/script/actions/CoreUtil.java

@@ -36,6 +36,14 @@ public class CoreUtil {
         return ColorUtil.hsbTosRgb(hsb);
     }
 
+    public static int[] hsbToRgbw(HSBType hsb) {
+        return ColorUtil.hsbToRgbw(hsb);
+    }
+
+    public static PercentType[] hsbToRgbwPercent(HSBType hsb) {
+        return ColorUtil.hsbToRgbwPercent(hsb);
+    }
+
     public static double[] hsbToXY(HSBType hsb) {
         return ColorUtil.hsbToXY(hsb);
     }