Why does your hair go ginger when you dye it blonde?

When you dye dark hair blonde, the underlying pigments in the hair can affect the final color outcome. Dark hair often contains a lot of warm undertones, such as red and orange pigments. When these pigments are lifted during the bleaching process, they can become more apparent, resulting in a ginger or brassy hue instead of the desired blonde. To counteract this, using a toner specifically designed to neutralize warm tones can help achieve a cooler blonde shade.