I made some small changes:
1. youtube and dailymotion icons
2. youtube logo (from black "You" to white)
3. close, meta (info) and net (beside full screen icon) icons
4. directory path font color (from black to white) at File Selection page
5. highlight color (from green to dark gray)
6. search background (from black to dark grey)
But I don't find yet how to make visible the checkboxes and I 'm still working on it.