Blue-black hair colour

[hairbyjamie]

Hey all. I had a client today who wanted to go from a level 4 to black with a hint if blue running through it (she explained she wanted something similar to an ink cartridge) so I mixed up 22/0 kolleston and added some 0/88 special mix. It came out ok but I wanted it to look more 'inky'
I was wondering what would you all do if someone asked the same?

 

[misskiani]

I sometimes use yellow 1:1 blue black, but when they want that pop of the blue in the sun, I add around 10g of crazy colour Blue for a more intense blue black. X