I looked at your pics, but I am not real sure so I hate to respond when I am really just guessing. So if I had to guess, I am leaning toward male. Just because the base of the tail by the vent is a little wider. I have a male that honestly, I was so convinced was a female! I kept telling the breeder I was so sure it was and it turned out to be male. Maybe wait a little bit, and post some more pics. Unfortunately, you cannot tell by colors at this early age.
Yeah this is a tough one for sure, so I was refraining from guessing. I'd suggest a little more time for your chameleon to develop before I could feel confident about my answer.
At 4 months it should be obvious but sometimes there are ones like this guy/girl who are still proving to be difficult. I believe you have a male but I'm with the others and suggest giving him some more time to develop and repost some pictures.