If you are bored of the only 10 accent color set available on Windows Phone, XDA Member,xorizont, has ported some cool Windows 8 Theme colours to Windows Phone using his Windows Phone app which works on any phone which can side load a XAP file.
If I am not wrong its around 27 Color sets, including Black and Grey that comes with the theme and is included on top of the list, from where you select your accent colours i.e. Settings > Theme. All the accent colours are available both in black and light theme and does not mess with the text readability anywhere.
How to install the App
To install this theme pack, you need to have a windows phone which can sideload XAP file and also have WP7 Root Tools installed. After you install the theme, you will need add the app as trusted app using the root tool. Done that, launch the app and tap on Install.
A response is not returned back, but if you do not encounter an error message, it means your installation is success and you can go to themes settings and choose a different colour.
You will notice that except Black, Grey and Orange, none of the colours are named correctly, but as Colour<Number> from 11 to 35. If you want to take a look on how it will look like, Here is the Flckr Album with all themes.
After playing around with couple of colours, I am petty happy with them as they vibrant and smooth and did not cause issues unlike previously discussed tools.