CSS overrides for CKFinder?

I'd like to override some aspects of CKFinder's styles to better match the site it's embedded in (fonts, colours, sizes etc - I'm already using config.uiColor), but I'd like to do so without touching CKFinder files, so I was wondering if there is some way of asking CKFinder to load an additional CSS file via config, or whether additional CSS rules can be supplied via the config or some other way that doesn't involve touching source files.