Without an example I can't help further.
K-meleon, tied to the system colors, as it uses the same interface by the OS (not as Firefox), may "change" colors for form elements (inputs, button, etc) by default. But is not a change, is apply your OS theme (but I think that FF or seamonkey applied it too).
Beyond that, can't help further.
In the other hand you talk about
Forum:
General