Blue hair?

I've been thinking of dyeing.. dying? whatever my hair blue for a really long time. Last time i did it was.. 2 years ago? and faded a littlee too quick, it was a pretty impulsive idea in the first place. Right now my hair is an interesting mix. The bottom half is black while the top half is bleached and last time i dyed it, was with permanent red dye(got tired of having to dye it red with semi permanent every week xd) It's still stained red tho ;-;. but blue's been on my mind for a while now. My question is how I could make it last? The dye i usually use is schwarzkopf Live, and this time im thinking of mixing together the turqoise and royal blue to get a nice in-between, not too dark and not too light. I'll keep the bottom half black though. and also what should i do to get the remaining red out? Maybe a bleach wash? honestly idk!!!! i'm realllyyy not the best with hair dye and hey this is my first blog post here too!!!! how cool