Maybe you could implement a random-color-permission?

public string GetRndColour()
		{
			System.Random rnd = new System.Random();
			string a = "#" + rnd.Next(0, 256).ToString("X2") + rnd.Next(0, 256).ToString("X2") + rnd.Next(0, 256).ToString("X2");
			return a;
		}​

Thank you for your suggestion, added in latest update

Hey, thank you very much^^

I have seen the permission already and set it for me, but it does not have an effect.

Szenarion:
1. permission.use granted
2. i have set a color for me
3. permissoin.rndcolor granted

will be still shown in my choosen color and not random.
Is there a new config file? Maybe i have to delete the old one?

Sorry, i am dump. Next time i will read the updated description, too :o
(i mean dumb, but it is kind of funny with p)