I'm not saying you're wrong, you are probably rightSee, I'm seeing a flesh colored comb, no pink/red at all. I'm just comparing mentally to the pictures I've seen of confirmed leghorn roos at 6 weeks, they have a good amount of color already.
I agree, leghorns just make things harder. I've also had mostly crosses myself, I'm just going off the pics I've seen here. Be interesting to see the bird in a few more weeks to know for sure.

I find it quite similar to the male on the right here.. except it has more development (the one in question) and is two weeks older.