User:Ched/admin-highlight
I originally used a redirect from user User:Mastcell's sub-pages to highlight admin sigs. I got curious and tracked down the original code from User:Amalthea, which led me to a rewrite at User:Theopolisme/Scripts/adminhighlighter.js. From there I just copied to my own .js file, then added an importscript to my monobook.js since I use the momobook as my skin.
I changed the colors a few times which are dictated by line 21 of the Theo code. Note that these numbers such as #AFEEEE is a hex designation for a color. You can find more colors through a variety of color wheels on the web, even google if you just put that #AFEEEE that into the search. If you want a simple view you can check out our page at Web colors. Note that there are 16 original colors that were designated for the old VGA system, and from there we used 216/256. Most are safe to use for even very old computer equipment, although most computers today can handle a much wider variety. You can visit X11 color names to see the current html versions/colors and hex numbers. It's best to pick one from that table to avoid clashes with different versions of web pages.