[url=(insert url)][colo=purple]K[/color][colo=orange]e[/color][colo=yellow]e[/color][colo=red]p[/color] [colo=pink]C[/color] (carry that on for the other letters then at the end finish your link by adding [-/url]
You can also see that I made color = colo but that was just so it didn't actually create colors. Same for the url. I had to add that otherwise it was going to create an acutal url so I added a -. you don't add these.
Just do colors and for shades you write "[-color=darkpink][/color] or [-color=lightred][/color] But some are hidden...once I typed in [-color=toxicgreen][/color] and it came up with a very bright blue. I don't the color list for signatures because they are different to the ones for posts.
The only reason I added these "-" was so it wouldn't actually do the color ;) Don't do that in your signature.