Garage doors need to co-ordinate with the finishes on your house. What you don't want is for garage doors to be a focal point. On many houses the garage forms the largest part of the front of the house. If they are very contrast-y then your eye will focus on them instead of the front door (which is usually where you want people to focus). An easy way to downplay the garage door is to colour it the same as the rest of the walls.

Post a pic of what you have now for the best advice.