Colour b4 frequent use?

[Stillmonday]

I'm going to dare to use Colour b4 to get rid of my black semi perm dyed hair.
Is the frequent use one ok? Doesn't sound as strong so might be better than the 'extra' one?

If it's black you're trying to get rid of I'd use the 'extra one'. Black is pretty hard to remove.
Though I'm talking permanents here - you say 'semi' so it should wash out.
If you meant permanent, go for strongest one you can. It's a PITA to use though I did get pretty much all the dark red out of my hair BUT i waited the stated 2 weeks and applied a blond dye on it and some of the red streaks reappeared so ended up doing some bleaching anyway but it's a good start.

I've overdone it with the semi permanents and it's clung in to my lengths and won't wash out.. I'm pretty scared to try the extra strength - I'm thinking it may harm my hair even more?!

No I don't think so, it's just removing hair dye. It's not like bleach.
Your hair will feel yuck once the process is over and may smell a bit so give it a good shampoo and put a good conditioning mask on and that'll sort that.
For me, it left me a strawberry blond because some hair dyes affect the inside of the hair but I don't think it's like that for semis as they just sit on the top of the hair.
You'll be just fine.
What's your natural colour and what are you going to do aftewards?

My natural color is mid brown although I do have some greys now, I'm wanting to get back to my closest natural colour but I'll need to put another semi color on to cover the greys

Extra strength will be better. I've used it about 4 times. Use a decent treatment conditioner for a few days after.

I've just got nightmares it's going to ruin my hair. I'm such a wimp!

It won't ruin your hair. Follow the instructions to the letter. Your hair will feel a bit drier, but it won't be ruined.

Did you do a strand test before? I'm assuming just clip majority of my hair back and do a few strands?

No you don't need a strand test.I would section your hair starting at the back, when
you use the colour b4 so thst you get a hood even coverage.
Don't use a permanent colour until at least 2 weeks after. If you colour again straight away use the 8 wash semi permanent NOT the 28 wash ones.
Like I said before follow the instructions to the letter and you really can't go wrong.

Ok thanks for the advice, I'm going to buy one this week