I've heard that once you bleach your hair, the hair that grows out (from the scalp) will also be damaged by what the bleach has done to the scalp/cuticle. Whether or not this is true, I would like to ask a question in a similar vein: will coloring the hair, using dye (black, several years back, in my case) still have an effect on what my hair looks like now?
I once coloured my hair, and then proceeded to grow it long, colouring it back to my natural haircolour. It was very clear that my hear wasn't as healthy as it could be, and I attribute that to the several colorations (one bleach, one red, two black to get it back). I got it cut off, and my hair is growing again now, and it's much more healthy, and I see no effects of the bleaching/dying I did those years ago.
New hair growth will not be affected by what was done before it grew out.
The old hair, the hair that was bleached and damaged, will always be damaged. You can make it look better, but you can't repair what's been done.
The new hair will be fine though.
Think of your hair like a water hose. Once the hose is damaged, or split, or whatever - you can repair it, but it's never the same. If my water hose gets split, I can duct tape it and it'll work okay, but it'll never be the same again. If I get a new water hose (new hair growth), then I'm okay.
See a professional - one who is long hair friendly, and get a deep conditioning. It'll help the old hair look and feel better.
How long will the effects of a deep-conditioning last?
I have a question that I hope you can be of assistance with. My natural hair color is a dark blonde or light brown. Anyways for many years I always dyed it a lighter blonde. Not too light though. Anyways. I have never had dark hair and wanted to try something different so i went with a dark brown. I really can't stand it. So after a little while of having dark hair and not knowing too much about dying your hair and not having the money to have it done professionally I bought some light golden blonde dye. I used it and you can barely tell. It just looks a little lighter. I am so unhappy with it. I was wondering if you could tell me how I can get the blonde hair back. Will I have to bleach it? Can I just buy some lighter dye? If you have any advice please let me know. Thank you.