For completeness, here’s my test code which includes the conversion from RGB to HSB and from HSB to RGB:
Required imports
import java.awt.Color
import java.util.List
// from RGB to HSB
val List<Float> hsb = Color.RGBtoHSB(250,150,50,null)
val float hue = hsb.get(0)
val float saturation = hsb.get(1)
val float brightness = hsb.get(2)
val String hsbString = hue + "," + saturation + "," + brightness
logInfo("scene.rules", "H: " + hue)
logInfo("scene.rules", "S: " + saturation)
logInfo("scene.rules", "B: " + brightness)
logInfo("scene.rules", "HSB: " + hsbString)
// from HSB to RGB
val int rgb = Color.HSBtoRGB(hue, saturation, brightness)
val color = new Color(rgb)
logInfo("scene.rules", "R: " + color.getRed())
logInfo("scene.rules", "G: " + color.getGreen())
logInfo("scene.rules", "B: " + color.getBlue())