The combat continues with the ever present brassy tones on blonde hair and it is true that bleached or lightened hair is more prone to having any impurities or stains show up, and can become brittle due to the chemical change. Since hair coloring goes through several stages it is essential to leave enough or even more time for the dye to have its full effect. I feel we need to process today’s blondes longer, adding 10 minutes more can make a huge difference in riding that unseen warmth that everyone hates and most hairdressers are too eager to wash the color off when it comes to blondes because they either feel that their timer is telling them to or "we think we see i'ts done" and of course the fear of breakage.
To eliminate this challenge it is more important to get that tone of blonde right the first time, not camouflaging it with toners which to me always come back dull and sometimes looking worse, think of it this way if the hair is open and porous and still contains warmth applying your toner acts like a temporary band-aid only. When the brassiness occurs a few weeks after the hair color has been done it might be attributed to the water, residues like iron and copper found in plumbing or the hair color has oxidized and absorbed as I mentioned impurities (environmental, smoke, medicines). And fighting this is easier with all the colored shampoos and conditioner available to us today. So before we are ready to wash off and tone a blonde push the color a little longer then apply the toner if you choose too, the blondes will all be happier for it.