Originally, I had mousy brown hair with subtle peroxide highlights. About a year ago, I made the mistake of going completely blonde. I went to a cheap Hair Salon and they coloured it a golden shade which went orange. They ran some blonde highlights through to break up the ginger, but I was left with brassy tones. The brassy tones eventually disappeared after the use of a silverising shampoo. After 6 months, my roots were over 2" long and my hair looked awful. I sought professional hair aid again (they had magically fixed it by dying it a dark ash blonde - shade 7). I thought all my hair troubles were fixed, but it was only temporary so my hair faded into a caramel swirl of blonde highlights, brown roots and unknown colours. The roots are now over 4" long and the blonde is getting boring, so I'm going to dye it back to dark blonde. But this time, I want to use a home kit but am not sure what the outcome will be like.
My hair is still in good condition after being bleached but will I have any extreme effects, i.e strange colourings or tints of green or orange?
Or will I have to dye my hair another colour in addition to achieving the dark blonde?
Please respond a.s.a.p I need my hair coloured by the end of the month.
Thank you.

It's hard to say without seeing it.

You run the risk of having two different shades of blonde, meaning where your virgin hair meets the already dyed hair. There is a possibility that you may see that line of demarcation. Not to mention an even distribution. Oh and let's not forget too ashy or brassy.

Your best bet is to go to a professional. If I were you I would not do it at home by yourself.

Going to a professional, they will be able to formulate the colors. You may need an additive.

I realize that it will cost money but in the end you get what you pay for.

Thanks :-)
At the hairdressers, do you think they'll end up merging several different colours together for the look that I want?
I'm sorry for my lack of experience, my hair anecdotes range as far as an all over colour and highlights, but that's it.

Of course they may. When I used to do hair, there were many times that I would combine different colors to achieve a certain look.

That's why it is important that you go to a professional. Your's would be considered a ”color correction” meaning that you have multiple colors going on not to mention your regrowth.

You could always get a free consultation from a salon. That way they could tell you exactly what they would do and the cost before you commit to anything.

Let me know how.it works out.