Muxtape settings: changing colour?

I’ve been trawling www.muxtape.com for this, but no joy.
Since I know there are some Muxtape users on here, I’m really hoping one (or several) of you can help me figure this out. I’m sure it’s very simple once you know, but I don’t.
How do I change the colour on my Muxtape? (blue is just not my colour)
I should add, I know how to do it, but I have no clue of the colour codes I have to use.