Thank you for your reply. But I didn’t mean to change the dark colour of the module, instead I’d like to change the colour of the links.
If you apply a dark class to a menu, for example (see here the “news categories” on the right: http://www.mathmods .eu/news), the links are grey and then the hover color is blue, which I like.
Instead, if you look at a K2 content module with dark class suffix (see here http://www.mathmods .eu/admission), the links are blue (whch is still ok, I quite like it), but when you put your mouse on it, it gets quite dark and difficult to read..
If possible, I’d like to have there the same link colors as in an ordinary dark module.