Quote Originally Posted by Konohamaru
I have a love hate thing going with Byakuya, the first time I saw him, I thought, yep, theres the bad ass of the show...then he releases pink petals which put me off him. Yet somehow he does such cool things. Dammit man, why can't you have blood red petals instead of pink, lol.

As for Mayuri, he hasn't done bankai yet, I think he's toying about as someone mentioned. I think all the captains will win their battle. Be a nice twist if one of them lost though.
The whole point behind the pink petals is the 'SAKURA' on his attack. Sakura are naturally pink...

Blood Red Sakura petals, I believe, have only been shown in anime (dunno about real life) when a corpse is buried under a Cherry Blossom (Sakura) and the tree absorbs the blood of its victim. This happened on Tokyo Babylon / X (from CLAMP) when Seishirou SAKURAzuka, the SAKURAzukamori killed his victims. And even he was shown besides pink petals...

The thing here is not the color... remember Sakura trees are really common (and famous) in Japan. And its most revered version is the pink one. Japanese have a full holiday to watch them bloom.