After 3 BB's and Colour B4, Where do I go now to achieve Pastel?

Try a couple more colour b4.

My god really!? 🙁  I can't afford 2 more and still don't really understand how a year old dye that was on a pixie cut would still be that present in my hair.  I know I sound stupid but I just don't get how it would be such a problem.

I'm afraid dyes can stain. All dyes, but especially dark ones. Sometimes nothing will get it out, sometimes colour removers will, sometimes bleach baths will... There's no one answer.

But, it's surely only the ends in that case though, if it was from a pixie cut a year ago. The rest of your hair is still orange because you're doing bleach baths, they only lighten a shade or two at a time, maximum. And colour remover won't do anything to remove natural colour. 

It was a short pixie cut as well, I've got darker bits where it's not possible for it to be because of the one time I dyed it dark brown.  I had put it down to poor application but then someone said about colour before.

All I'm really concerned about is my hair breaking off.

Even without old dye, you are not going to get white enough for pastels with just 3 bleach baths. You need to be patient and keep doing them, (space them out more and reconstruct in between if you are worried about damage) or bite the bullet and do a full bleach. Getting to an even level 10 so you can do pastels is really difficult, there are no shortcuts or quick fixes. It is impossible to go that blonde without damage too, you will have to sacrifice some length.
If you are convinced the darker bits are not old dye, then it is probably uneven application. Are you covering the hair once the bleach mix is added?
What bleach are you using? It can make a huge difference to the amount of lift and also the amount of damage.

Now that I know I'll have to do more BB's I'm fine with that, just wasn't sure how many I would actually have to do.  I'm using the trulites bleach, I know it's not the greatest but it hasn't damaged my hair as much as those darn box dyes which is a plus side for me.

And yes I've been covering it, I think I must have just cocked up the application.

Just to give you some perspective - I have natural level 3 hair, did multiple color removers, 3 full strength 20 vol bleaches and 3 20 vol bleach baths(over the course of a year) and my hair is still not quite light enough for pastels.  It is about a level 9.  I have had to lose quite a lot of length as well.  When I do my roots I do full strength 30 volume(with high quality 9 level lift bleach) and they only go to level 9. 

I would invest in a really good bleach (Wella Blondor, Schwartzkopf BlondMe, Matrix light Master, Loreal Infinie Platine etc) and make sure you are applying it really liberally and thoroughly. It is normal for hair to go from brown to red to orange when bleaching, as you progress you will get to gold then yellow. For pastels/white you need pale yellow/cream, the colour of the inside of a banana.
You could always have a break and dye what you have now a colour you prefer if you are totally sick of being stuck in orange.

You could always have a break and dye what you have now a colour you prefer if you are totally sick of being stuck in orange.

I am considering this as I'm going out for my birthday in a week and wouldn't feel very confident with the current colour.  As well as that I think giving my hair a break would be the better option, I'll mull it over a bit.