Generally, I would easily say that PES3's Editing features are far superior to those of PES2.
Barca away is one of the toughies, however.
Try this:
Shirt - 2 Row, 18 Column. Colors - 1: Light Gray, 2: Blue 3, 3: Light Gray
Pants - 3,1. Colors - 1: Light Gray, 2: Blue 3, 3: Light Gray...