Hi Miku! She's not from an anime so she's my cover photo. Happy? Anyway, blue is the greatest anime hair color ever, mainly because of the women.
Sinon is our first lady in blue. The avatar of Shino Asada from SAO2 is a beauty indeed and almost sways kirito in a sandy cave...
Imai!!!! She's from Gintama... Very feisty for a blue haired character. She's also an oddball.
Xenovia! High school dxd definitely counts as an anime. She's a hotty with a thing for Issei the MC
Rei Ayanami! my personal favorite is from the anime evangelion. If you've seen it, nuff said... If not, go watch it right now.