My hair is mouse brown normally and I frequently switch between colours. I personally recommend Loreal because I feel the colour swatches on the box are the most accurate of the brands even when your hair has colour on (like yours does now). If you want to see how much your hair can handle, take a small piece from somewhere unnoticeable and cut it off. Only like an inch, then wet it and try to stretch it. If it stretches a bit you're good to go, if it breaks you should deep condition for a week or so before starting. Be prepared that whatever you do some hair will come out, usually for me about twice what I lose in a normal shower comes out per dye, but that is a very nominal amount.
I have a bad experience of the bleaches you can pick up in superdrug and am not confident mixing my own so I used two bottles of: http://www.boots.com/en/LOreal-Feria-Extreme-Platinum-Power-Hair-Dye-L01_1282011/
DO NOT take off the dye when your hair starts turning orange as when the bleach starts to process it goes orange then the colour of the outside of a banana then the inside of a banana. That last pale yellow is something you can work with but any of the others will require a repeat application. Also, if you want it to look natural I suggest you apply to the ends and mid-lengths then to your roots about ten minutes in, as roots tend to absorb colour faster, bleach hates your scalp and you will end up with a translucent half centimetre at your hair line which can be strange to see.
Re-do the platinum dye if need be, it's better to do that again then to try and cover up the bright brassy yellow later. Regardless you will need to go to http://www.beautybay.com/ and look at their Wella Colour Fresh purple bottle toners. Definitely have one of these ready for application after the bleach.
When avoiding warm shades in your hair (and the horrible orange/yellow disaster) you need to be pro-active. This is not much hassle, just replace your usual shampoo and conditioner with one that has 'silver' in the name. These will come out VERY purple and my favourites are Clynol Reflex Silver Shampoo which is available in some salons or at Sally's salon services shops (student discount on Tuesdays) or Lee Stafford's bleach blonde range which is less expensive. Lee Stafford also does 'hot shots' which give a burst of toner. Don’t leave these on for more than a few minutes or you’ll get a purple tint.
Now the condition of your hair. I use Tresemme Keratin shampoo and conditioner which makes my wavy hair dry straight, and I am a big fan of Lee Stafford argan oil hair treatment. This is excellent because it goes between shampoo and conditioner so you can still condition afterwards. If your budget permits then also get Kerastase Ciment Thermique which is a 'milk' to put on the ends of your hair which seals split ends. You only need a pea sized amount each time so the bottle lasts forever. I also recommend John Frieda Frizz-Ease serum (again, lasts forever) and just rub it through to tame flyaways and frizz, as well as Lee Stafford de-humidifier spray for the hair line, as bleached hair tends to decide to bend and curl at will and this stops you from getting a helmet head.
Here are links to some of the products I mentioned:
· 6 years ago