[y3llo_w]

so basically as the title suggests ive never used semi permanent dye on my hair:s But i want to dye the underneath of my hair blue!...only since im blonde im kinda worried it might fade to green or worse still run and turn my all my hair green!

does anyone have any tips/experience in using semi permanent colouredy dyes?

[fran.ha]

For blue you need the whitest base possible.

Depending on how pale your blonde is, you might be able to just blue it up now. Do a strand test to see what the colour comes out like on your current hair.

If it comes out too green based (because of the mix of blue in the dye and yellow in your hair) then you'll have to lighten up to as white as you can go before the strand test performs as you wish. You can bleach bath in order to do this as it's less damaging and because your hair is already blonde you shouldn't need to do much.

Yes, blues will fade. They fade very badly actually. They will fade to either green, yellow, or grey colours. This thread is pretty useful for looking what blue dyes fade to what.

All dyes fade, essentially. So to keep the weird colours from coming you'll just have to keep topping up. Wash your hair as little as possible (once a week if you can) to minimise fade. Use vinegar rinses to minimise rub off and running of colours.

[y3llo_w]

Awh thank you for your reply that thread is really useful!

My hair has already been bleached even blonder to a whitey blonde colour..so I should be okay from that perspective..its just the fading to green I'm worried about"/ once it fades to green is there any way I ccan get it out really fast or dye over it to get rid of the green?:s

[fran.ha]

(Original post by y3llo_w)
Awh thank you for your reply that thread is really useful!

My hair has already been bleached even blonder to a whitey blonde colour..so I should be okay from that perspective..its just the fading to green I'm worried about"/ once it fades to green is there any way I ccan get it out really fast or dye over it to get rid of the green?:s

You'd have to dye over it with something darker, like brown or red. It probably won't fade to green though, look through that thread. Most blues are purple based and thus fade to purple or pink.