The overwhelming majority of rainbowfish don't develop their most brilliant coloration until a certain level of maturity, and most are still rather dull in adolescence compared to their adult counterparts. The maturity level needed for color development varies by species. I know it does take Boesmanis some time to develop their color, but I don't think it's anything like two years, probably more like a few months (although the colors may reach full brilliance at two years). I know most Boesmanis I see in the LFS have either *just* begun to develop the first tinges of their adult color or have not begun to change yet. They're also typically still only a couple of inches long, which I assume indicates adolescence. Most dwarf rainbows I've seen in the LFS do have the right colors (metallic blue sheen and bright red fins), but they're not brilliant yet. I assume they're only adolescent fishes, and the brilliance develops as they mature.
Also, as heresmike mentioned, the coloration of rainbow females is typically muted (sometimes *very* much so) compared to the males, although it's quite unlikely that out of seven fish you got all females. They're probably just all in various stages of adolescence.
Carrcn, just hang in there and be patient. I'm sure your rainbows will develop in time.
pendragon!
