Not sure if the Bucco Uni spectrum is broad enough for this to work, but between the vests, throwbacks, and alternates I think they could swing it. Though I pity the team that gets stuck with red vests.
Either way, this is was a huge win-win for everyone, and a cool thing for them to do. I think what really makes it stick for me besides the cost to them, is how awesome it is to see them put connecting with the community and building fans ahead of any short term losses in merch sales (every kid got a free authentic jersey and hat to keep). The benefit for them get 11,000 kids running around in Padres colors instead of someone else's.