Frontend colour switcher for Wordpress?

Hi,

I am wanting to build a site in Wordpress where the user could switch colours - in a very basic way - very much along the lines of what you can see on this website: http://www.walesdyslexia.org.uk (the colour switcher panel in the top right in the main navigation area).

The switch would just be to give a different colour for something as basic as basic as headlines and panels in the way shown on that link.

Is there a plugin - or even a theme - that already does this? Or is it something that a designer such as myself could add through code? (I’m not really a coder!)

Any advice, links, tips would be really appreciated.
Thanks.

Not sure if you’re able to find a plugin for that but if you’re interested in, I could provide some custom work.
In case of interest, please, drop me an email