I know someone's gonna chime in and say this so it might as well be me... SEARCH!!! This has been discussed before in great detail. It's kinda pointless to have 50 threads on how to paint a piece of plastic...which I will go ahed and tell you how to do...
1) Remove emblem (look up how to do it) (*floss/fishing line for the rear, just pull the front off*)
2) Remove tape stuff from emblem (rear only)
3) *OPTIONAL* Sand emblem
4) Put new tape on rear emblem
5) Apply adhesion promoter
6) Apply paint (krylon works good or and high temp paint or whatever you want. I'm sure people will have their own opinions)
7) Repeat step 6 2-4 more times (remember to use light coats)
8) Apply 2-4 coats clear (light coats)
9) Put emblems back on car
10) Get in car
11) Start car
12) Drive car with new black emblems
13) Park car
14) Admire new emblems
15) Close thread (admins only)