Camouflage is the color of cowardice! *BLAM!*
Eh, I'm not too sure, but apparently a writer at Games Workshop really like the Ulatramarines and kind of wrote them to be way too OP when they shouldn't be.
Personally, my first real experience with the 40K universe was Space Marine (the game) and Captain Titus of the Adeptus Astartes Ultramarine Chapter. So they've got a special place in my heart.
Ahhhhhhh, I see. *Shrugs* First experiences usually imprint on us, for good or ill; it would explain why my taste in women likes them a little on the heavy side. My first 40K experience was with the first three books of Dan Abnet's Ghosts
series, and they're still my favorite Guardsmen.
They, however, make strategic use of camouflage; when you're not a 9-foot tall behemoth in plate armor, everyday things like demons and chainaxe-wielding cultists push little people to use more of their available talents.
On the subject of gaudy armor, though, let it be known here and now: Skitarii wear it better.