More concept helmets is always good! 
I like your second design. I think that captures the essence of the emblem.
I think a white base overall with some very light gray weathering would be a good way to go. Some careful taping and masking could give you the nice, broken yellow stripe going front to back over the dome, and the same with the red and beige stripe going around the circumference.
Not sure what to recommend about doing the emblem. . . if you scale it and print it out as a template, you could trace the outline onto the helmet and paint it on with a small brush.
Interested to see how it turns out. 
