I have several Dark Cornish about this same age. Two roosters and 1 pullet, and 15 that are about 6 weeks old. My roosters still have some brown on them but not as much as they did have. Their black feathers are beginning to shine quite green whereas the pullets feathers are not. I can already tell which of the young ones are going to be roos and which pullets.
This is my hen at about 3 months. Her comb has turned gray.

This is one of my roosters at the same age (these were taken June 26th)
He has an obvious red comb.

The other rooster...

Actually when they are more upright their legs are longer but not "GINORMOUS" :) and I had always thought they had short legs when I looked at pics before mine grew this big.
To me, yours both look like roos.
Edited by ESofVA - 7/26/12 at 3:29pm