Better rainbow code

[inxomnyaa]

Good morning my friend. I fiddled around a bit, and figured this code works better and is cleaner for rainbow color fading:

	private function updateColor(int $step): Color
	{
		$center = 128;
		$width = 127;
		$frequency = 100;//controls change speed
		$red = sin($frequency * $step + 2) * $width + $center;
		$green = sin($frequency * $step + 0) * $width + $center;
		$blue = sin($frequency * $step + 4) * $width + $center;
		return new Color($red, $green, $blue);
	}

$step can be the current tick. $frequency controls how fast/much the colors change

Original code and read-up can be found here: https://krazydad.com/tutorials/makecolors.php

[Enes5519]

my friend, I'm away from this stuff, but thanks for your advice. I will approve if you send a pull request.