Color.kt

sealed class Color {
    object Red: Color()
    object Green: Color()
    object Blue: Color()
    class Rgb(val r: Int,val  g: Int,val  b: Int): Color()
}

fun main(args: Array<String>) {
    fun color(c: Color): String = when(c) {
        Color.Red -> "#FF0000"
        Color.Green -> "#00FF00"
        Color.Blue -> "#0000FF"
        is Color.Rgb -> "#%02X%02X%02X".format(c.r, c.g, c.b)
    }
    val color_hex = color(Color.Rgb(255,255, 255))
    print("$color_hex")
}