Here is how to use colors for item names and block names, and well anything really!
Firstly, in your add name method (LanguageRegistry.addName(par1, par2), before your item name, you want to put:
\u00a7a
However, this will give you bright green, to change the color, replace the last letter (the a) with one of these letters OR numbers:
0 - Black
1 - Dark Blue
2 - Dark Green
3 - Dark Aqua
4 - Dark Red
5 - Purple
6 - Orange (Gold)
7 - Gray
8 - Dark Gray
9 - Indigo
a - Bright Green
b - Aqua
c - Red
d - Pink
e - Yellow
f - White
source - http://www.minecraftforum.net/topic/1764612-151-mads-forge-modding-tutorials-wip/