What colours stain hair?

Blacks, reds and any dark shades all stain. Any colour that is applied repeatedly or over bleached hair will also stain. It isn't down to brands or individual colours, permanent dyes alter the structure of your hair, they aren't designed to be removed hence the term 'permanent'.
Demi permanent dyes also alter the structure of the hair, they don't completely wash out after the 28 washes it promises on the box, and your natural pigment has been removed. The colour molecules aren't driven as deeply into the shaft though, so they are less likely to stain than a permanent.
Even true semis can permanently stain though. It really depends on how porous (ie damaged) the hair is, and how many times the dye has been used.

You can try bleach bathing the darkest parts of your hair, then using more colour removers. Often the bleach opens the cuticle enough to make the remover more effective. It can take a few months to get black out safely, but you should be able to get past dark brown to some shade of red at the least.
Make sure you apply the remover to clean, clarified hair without any conditioner on. Keep it covered and warm and leave it on for the full hour. I had good results doing one every couple of weeks and using regular fading methods in between.

Brilliant, thank you so much Wicked Pixie, what suggestions do you have for the bleach bath? straight shampoo or a combo of conditioner and shampoo? also what bleach ration would you suggest?

I prefer to use a lower vol peroxide, generally 20 vol, and use the same amount of shampoo as peroxide. So one scoop bleach powder, 2 scoops peroxide, 2 scoops shampoo. Others add the same amount of shampoo/conditioner as the overall volume of the mixed bleach. (which would be 3 scoops in this example)
I have never actually tried bleach bathing with conditioner, although I am sure some people on the forum must have tried it. I like the consistency you get with shampoo, it  is easy to squidge through the hair and get good coverage quickly.
Definitely try on a strand test to check for timing and to see how your hair is standing up. Remember that bleach damage takes a good few weeks to fully show, so go steady, i would only leave the mix on for 10-15 minutes tops.

thank you 🙂 it didnt go exactly to plan and i ended up using less shampoo than i think i should have but i have a banana peel blonde and orange/copper ends now so will go slow from here out, i will try your suggestion next time, i used 6% with blonde me and only about 4 pumps of shampoo, much lighter than i expected with my strand test but the ratios just didnt equal the same when i did the overall result, you learn eah 😉  *ott*