Wow, nice bottle, too bad it is cracked.
It is definitely not a reproduction! It appears to be the GXI-7 mold as listed in the McKearin flask book.
You would be talking thousands for value if perfect - now hundreds given the crack.
If I had to hazard a guess I would say the color is olive green - one does on occasion see some of the Pikes Peak flasks in this color, but most often aqua.