chickensducks&agoose :
I vote yes. all my ducks paired off based on color, not breed or age. I've got 3 2 year old blue, black and splash swedes, and they each paired up with a similarly colored duck. the splash paired up with our 1 year old pekin, the blue paired up with a runner, and the black swede paired up with a 1 year old cayuga.. so i think they prefer their own color. Birds of a feather, and all that.
My ducks did that too, for the most part, but I had a group of 4 that were hatched together, 1 duck and 3 drakes. The duck was a blue cayuga, the drakes were 2 rouens and a rouen/cayuga mix. They stuck together all the time. My pekin group has 2 rouen drakes as well, though I think they are mostly body guards. Most of the pekin eggs I hatch are pure. Then I have a pair of rouens that have matched themselves up. My other black cayugas (1 drake and 2 ducks) grouped themselves together as well.
But in your case, I wouldn't count on it. If you raised them from babies in their own color groups, they'd be more likely to stick with their own groups. But geese are different, I recently bought an adult toulouse who promptly made friends with my embdens. Granted, the only other toulouse I have is a baby, so the adult either had to be alone or with the embdens, but it had no hesitation whatsoever moving in to their little family and taking care of the babies
If you want to make sure you have pure colors for breeding, just be sure to pen them up from about February through June, depending on where you live