I got traded a Pokemon and I wondered if you could find out the gender of the original owner's player OT.
The OT will be highlighted as blue if it is a male Trainer and red if the Trainer is female in Generations III (except in Pokémon FireRed and LeafGreen), IV and V.
However I'm not sure if this is also the case for Gen VI.
Source: http://bulbapedia.bulbagarden.net/wiki/Original_Trainer
Hope I helped :)