MainScreen.kt

@Composable
fun RandomColourButton() {
    val scope = rememberCoroutineScope()
    var buttonColor by remember { mutableStateOf(Color.Red) }

    Column {
        Button(colors = ButtonDefaults.buttonColors(backgroundColor = buttonColor),
            onClick = {
                scope.launch {
                    while(true) {
                        delay(500)
                        buttonColor = Color(Random.nextInt(0xFF), Random.nextInt(0xFF), Random.nextInt(0xFF), 0xFF)
                    }
                }
            }
        ) {
            Text("Cycle Random Colours")
        }
    }
}