How to transition from red dyed hair to own shade (or one shade lighter) with highlights, without re-dyeing the hair?
Find a semipermanent dye to apply to the dyed part to get it closer to your color–try a drabber ashy color to take out the red. When you have enough roots try having the hairdresser add highlights to tie in the colors and keep up the drabber color. The condition of the dyed part won’t be wonderful, but the damage is already done. Concentrate on keeping the new growth healthy. Try buying shampoos and conditioners for damaged, colored hair. They do work. And get the dyed part cut off regularly. You’ll see you far you have to go and it’s not so bad.