If you got the erroneous color any good skilled hair colorist will be happy to amend it. Of course you might want to think twice about recurring to the same person who originally created the mistake.
IF your hair was highlighted and then you have changed your mind and decided that you are not satisfied or because “this very light color is not your thing”, then it was not the hair colorist fault, go back and explain to the professional that you have changed your mind and she/him will simply apply a darker toner to calm down the tone to the shade you like better.
If TOO-DARK-COLOR is the case… don’t fright!, after several days of washing the hair, it usually lightens.
For help from experts on "Hair color correction", please visit our page "The Best of Hair Color"