Hi Alexander,
You could use a different skin. Another option is if you just want to do it for a specific feature you can use a more specific css selector like
.htmlmodule .modulefooter {}
or
.linksmodule .modulefooter {}
I'm going to be adding a new setting that allows adding a custom css class on the container for feature instances, so once that is done you will have the ability to specify a custom class on each content instance and then you could do it with
.yourcustomclass .modulefooter {}
but for now you could do it at the feature level or by using a custom skin.
Hope it helps,
Joe