I was wondering, I just did my first jam session with a potential band today. And it was a blast. But the only problem I noticed was a slight difference in that our tones were different etc. so when we'd play parts w/ the other guitarist it would just sound sort of funny transition from whatever he was playing to mine.

And also i'm supposed to be the lead so i know that i'm just slightly (very slightly) louder than the rhythem.

Any tips on mixing?
your tones don't have to match but they do need to compliment each others, typically rhythm should have a warmer tone and leads should have a brighter tone. as for making your lead stick out you really shouldn't be but just a tiny bit louder and actually if you have a chorus pedal or something that adds a bit of thickness to your leads then you should probably be able to play at the same levels. just some basic mixing tips here
normally, even at the same levels, the little bit of extra treble that should be in the lead tone should bring the lead guitar towards the front. You can use tones to achieve 3D qualities to your music.