I agree with mech500 that white looks too feminine.
I think blue would be difficult to call out. I've seen gen 1500 with blue dial a few times and every time it looked different depending on the lighting.
You would have to see them side by side in the same lighting but I think they would look be pretty close.
I don't see the feminine, maybe a flashier (white/silver reflections) watch than I'm used too, but I wouldn't say feminine unless your talking about a female lumberjack that moonlights as an Elvis impersonator. This is a thin but a watch with substantial wrist presence.
I agree the blue would be difficult to call out and it was my first choice, but I have enough blue dial/insert watches. Eventually if I end up really liking the 15400, I'll probably pick up a blue, too. I'm still not sure on the black, especially since I just pulled the trigger on a Diver, and I already have so many black dial watches. It's hard to justify another one, because there is always another black dial watch I like. Always...
At the end of the day I don't think you could go wrong with any of them, 2 of them, or all 3. It depends on you and your collection.