User blog comment:JoePlay/Creating Your Wiki’s Design/@comment-26478829-20171213095707

I usually take screenshots or use artwork from the series my Wikia is based off of that, in my mind, shows off the color and atmosphere of the series the best, then I put those screenshots in PaintDotNet and use the color picker tool to extract the hex color code for the colors in the picture, then I can use its editing tools to finetune the color.

It's not a surefire method, but it's worked for me in the past. As others have said before me, simplicity and familiarity are key. Outside of a few holiday coloring (Halloween, Christmas, maybe Easter), I try to stick to a single theme unless I plan a complete overhaul.

My rule of thumb has always been this: If the customization makes reading harder then it needs to be, it should either be tweaked or removed all together. That's why I never use transparent wiki pages with busy backgrounds. Readability and content first, looking nice a distant second.