(This theme only targets C/C++, other themes may target more than these languages.)
I'm on Windows, for slightly different Linux steps see here.
My chosen theme:
Download your chosen theme, there are a number here. (I actually just viewed the raw source and used File/Save in the browser.)
If the file downloads as 'yourtheme.conf.txt' then remove the '.txt' extension.
MAKE SURE CODE::BLOCKS IS NOT RUNNING
Go into the CodeBlocks folder; mine was at C:\Program Files (x86)\CodeBlocks. Run the application cb_share_config.
If the 'Destination configuration file' doesn't appear on the right then click the ellipsis (..) and it will take you to the correct folder. Mine was C:\Users\Andrew\AppData\Roaming\CodeBlocks.
Copy this location and then go into it from Windows Explorer. Copy and paste the file default.conf - I wanted to keep a copy of it in-case things go pear-shaped.
Return to the cb_share_config app, or re-start it if you exited it.
Press the ellipsis (...) next to 'Source configuration file' and find your new theme file.
Tick the three boxes on the left that you see in my screenshot - you may not have three.
I'm not sure of the difference between these so ticked them all. Read all comments below in-case someone elaborates on what each of these do, and whether you need, or want, them all.
Press the Transfer button, and acknowledge any messages. You will then also have to press the Save button (center-bottom of the dialog).
Okay, you can now exit this application and start Code::Blocks. You may have to go to the Settings menu, Editor, click the Syntax Highlighting button in the left-panel and select your theme from the 'Colour theme' drop-down at the top.
There was one more thing I had to do with my chosen theme, which was to change the default caret colour, as it was invisible!
In the same Settings, above the Syntax Highlighting button on the left is one for Margins and caret - choose a sensible caret-colour, and/or size, from here.
This post has been edited by andrewsw: 29 July 2014 - 08:47 AM