Hello,
I'm no sexing expert however, if that is a panther chameleon (you didn't specify) and it is 7 months old, than I believe you have yourself a girl. Usually, if it is a Panther, @atleast basic coloration would of shown between 4-6mos based on my experience. The fact that it is 7mos old and at that coloration, seems to me like a female. In a nutshell, your cham isn't colorful enough to be a male, if indeed a panther.
In addition, the bulge under the vent is not big enough. It looks to me there are no Hemephenes (cant spell it, sorry). Maybe there is a bulge and it just doesn't show in the picture. I know that in my 6 mo old Amanja, his male organ bulge is very noticeable.
This is just my opinion, I could totally be wrong. However, Male or female, your cham is beautiful.