code

ColorUtils.kt

    private val startTime=System.currentTimeMillis()

    fun hslRainbow(index: Int,lowest: Float=0.41f,bigest: Float=0.58f,indexOffset: Int=300,timeSplit: Int=3000):Color{
        return Color.getHSBColor((abs(((((System.currentTimeMillis()-startTime).toInt()+index*indexOffset)/timeSplit.toFloat())%2)-1)*(bigest-lowest))+lowest,0.7f,1f)
    }

usage(Arraylist.kt)

"riserainbow" -> ColorUtils.hslRainbow(index+1,indexOffset=100*rainbowSpeed.get()).rgb

image