I've seen really plain babies born out of the flashiest moonspotted parents, and I've seen goats with only one or two small moonspots produce heavily moonspotted babies. Since all you care about is color, I'd go for the buck you like the color of best- the difference between the kids the two brother produce will be negligible, and it's all a crapshoot anyway. I had a buck absolutely covered in moonspots last year who only produced one kid out of 5 with moonspots. I have a doe who I don't even see any moonspots on, but she must have one somewhere because her kids usually have a couple small moonspots.
I'd really suggest taking the conformation of all goats involved into consideration too though, not just color. Even if you're just a pet breeder, you need your goats to be able to hold up well as they age. I didn't look too closely at the photos but one of those does has an incredibly steep rump, so you might consider whichever of the bucks has a better rump angle.