Do you have to bleach

Hi there. Yes if you have dark hair, it is best to bleach and pre lighten the hair, to get the brightest colour possible - as this dye does not really show up on dark hair.

How would you compare directions to manic panic?

Directions does not bleed as much and has longer staying power than Manic (with proper care after coloring). Directions also has a wider array of colors and their colors tend to be closer to their color wheel than Manic.

I am looking for a blue that will stay in my white/grey hair--other brands have washed out in two washing--does this one work better???

A lot of semi color fading has to do with maintenance after dyeing. Make powdered dry shampoo your friend and wear a shower cap when showering. If you do water shampoo your hair, use only sulfate free shampoo and keep that to a minimum. Also, cold water when shampooing helps keep the color.

Does it wash completely out, or does it just fade and you have to dye over it to get it out?

I used directions violet and diluted it with conditioner for a pastel and it did not wash out all the way for me. It could be different for you but it's very unlikely that it will all wash out.