Whoever said textures being in the gct file, um what? Textures aren't in the gct file. They're in seperate folders on the sd card. With the latest file replacement code, it's:
( X: )private/wii/APP/RSBE/pf/fighter/(character's name like it is on the disc)/Fit(character name like it is on the disc)(color number).pcs (or pac)
replace X with whatever drive the sd card is in the computer (mine is usually F)
Note: if the color number is say, 02, then it won't necessarily be their third color (00 is first color).
color 02 might be their last color, or fourth, or second, etc. just go to the texture guides, really.