If you want to be able to make your own custom colors for London without using another website's colors, but don't want to get lost in writing the CSS source code yourself, I am working on a LESS source project for the London Theme that can be compiled to CSS.  I'm open for suggestions.  Admittedly, it's unfinished and I think it can be simpler.  If you are on GitHub and like it, please star it!  :)

Hi Joshua,

That is really cool, thanks for sharing!

Tiago Simões