Are you using the WYSIWYG editor? If so that is different that the "Basic Editor" that I gave instructions for...
If you are using the basic editor at that didn't work than somewhere in the template the color is probably hard coded,
You said you don't know how it changed... You could disable hooks and see if you still have the problem, if you do it's a mod causing the problem.
To disable hooks add this line directly below the first line of your config.php:
Code:
define('DISABLE_HOOKS', true);