Alas, the title's a pun -- only one of these offices is in Brooklyn.
Nearly all collectors have a specialty. Some baseball card collectors only go for rookie cards; maybe some video game addict collects various Pac-Man machines.
Some postmark collectors collect "thematically" -- cancels from towns whose names contain, say, their own name (Like my visiting here); types of waterways (like Lake Milton, OH and Riverside, AL); trees (Glen Oaks, NY and Maple Valley, WA); or colors. Presenting a few random shots of the "spectral" variety:
Of course there's also Orange, NJ and White Plains, NY. Can we round out the rest of the spectrum? Say Silver City, NV; Blue Hill, NE; Golden, CO; Black Earth, WI; and Brown U. Station, Providence, RI.
There are dozens for the major colors -- consider Green Bay, Greensboro and Greenville -- so let's try to be more subtle. Though maybe not as subtle as Olive Hill, TN. There's got to be a sweet spot. Are there any post offices out there with Violet or Purple in it?