I used to be a beautician so the info I have may be a bit old, but... I have almost black hair with lots of red in it. When I was working, I did manage to get a spot that was platinum.

Ok, first, your roots, if not let go for too long, will bleach out all the way because of the warmth of your head.

Second, if I was you, I'd be globbing in the Mayo, yes, mayonaise, on my hair, wrapping it in a plastic bag, and either sitting out in the sun to warm it or applying very gentle heat with your blow dryer. Leave the mayo on for about half an hour and then wash it. After a couple of treatments or so, depending on the dryness of your hair, the luster should return.

What I did when I had the one platinum spot on my head, as well as now that I have grey hair is use Roux Platinum (which is really a light grey) or White. There is also Silver Lining. It's a rinse that washes out with the next shampoo so you'll have to apply it every time you wash your hair. Also, take care that you get it on evenly. Comb through, with a wide tooth comb, to make sure it goes on even.

The blue and purple streaks are no doubt where your hair is more porous. Go to the beauty supply and buy "Protein". It's in a clear, liquid form. Apply it all over your hair, comb it through with a wide tooth comb and make sure your entire head is saturated. Leave it in and style your hair. You can add any other product after you have applied the "Protein."

Something else you could get is a filler to fill the more porous hair. I believe you saturate your hair with it, leave it in for a while and then rinse it out. It's colorless. It can also be applied in the toner. Yes, you need toner. I seriously doubt that you can get your hair completely white with just bleach. The toner is what tones out the yellow. It, too, has peroxide as in the bleach.

What color is your hair naturaly, BTW? How many times has your hair been bleached completely? Be very careful with that, ok? It's already breaking, isn't it? The "Protein" will do wonders for the breaking as will the mayo. Mayo has oils and protein in it. No need for fancy treatments that don't work, anyway.

Good luck and let us know how everything works out, ok?