What fish do you have with him? at that size you should see ALOT of color. Mine usually color up when they are ~2inches- I had a female lay eggs at that size, but she was too small to defend them fomr the rest of the tank.
If they aren't flashing good green color, check these things: tank mates, water quality, food
If they aren't flashing good green color, check these things: tank mates, water quality, food