Radio Buttons in Admin – CSS clues?

Hi – a bit of a dolt question possibly:

I am learning a huge amount about CSS from these forums, and by gently hacking some of the wonderful themes you guys build. *respect*

Currently changing wp-admin.css so that the admin panels for a couple of different blogs I support are *clearly* different.

Question: Can I change the colour of the radio buttons used in Admin (e.g. on the Upload page)?

If so, a few pointers/clues would be much appreciated. It’s not the biggest issue in the world, but I am now curious, and you guys seem to respond well to curiousity!

P.S. I am comfortable with my dolt-ness. :o)