German Infantry, Wermacht, Berlin, end of WW2

Hello,

A friend of mine builds a 1/35 diorama using Dragon's wermacht infantry figures.

My questions are:
1. what colors does he have to use for the uniforms for that theatre in that era - please write a formal code such as FS or RLM or a commercial paint code (model master/humbrol, etc.)
2. can you direct me to a good website where my friend can find such information for other german units and other theatres and WW2 periods as well?

Thank you very much!!