Toning blonde hair is a process that involves adding toner, a semi-permanent hair color, to counteract unwanted brassiness or yellow tones in blonde hair. This can help to create a more desired and cooler, ashy blonde shade.
Blonde hair toning is important because it can help to maintain the desired shade of blonde, prevent brassiness and yellowing, and add shine and vibrancy to the hair. Historically, toning blonde hair became popular in the mid-20th century as a way to enhance the beauty of blonde actresses in black-and-white films.