MainActivity.kt

@Composable
fun FlashingCountingButton() {
    val scope = rememberCoroutineScope()
    var buttonColor by remember { mutableStateOf(Color.Red) }
    var count by remember { mutableStateOf(1) }

    Column {
        Button(colors = ButtonDefaults.buttonColors(backgroundColor = buttonColor),
            onClick = {
                val job = scope.launch {
                    // launch a separate coroutine, inside this one, to increase the count
                    launch {
                        while(true) {
                            delay(500)
                            count ++
                        }
                    }

                    //...and here we change the background colour
                    while(true) {
                        delay(500)
                        buttonColor = Color(Random.nextInt(0xFF), Random.nextInt(0xFF), Random.nextInt(0xFF), 0xFF)
                    }
                }

                // cancel the above coroutine after 5 seconds
                scope.launch {
                    delay(5_000)
                    job.cancel()
                }
            }
        ) {
            Text("Cycle Random Colours (count = $count)")
        }
    }
}