If you’ve ever done laundry, you know that bleach stains dark clothes and brightens light ones, but why does it do that? Well, the answer is all down to chemistry.

Inside the dyes we use in clothes, food, etc., there are chemicals called chromophores. These chromophores reflect a specific wavelength of light, causing them to appear a certain color, like purple in the case of the water in our video.

However, when bleach is added to the equation, it goes through a process called oxidation, releasing oxygen molecules. This oxygen reacts with the chromophores, breaking up the chemical bonds between them. With their bonds broken, the chromophores reflect less color, an altered color, or even a wavelength of light outside the visible spectrum depending on the type of dye in use. The reduced or invisible color reflection is just seen by our eyes as white, making light colors look lighter, and the stronger dyes like the dark purple water shift to another color, appearing as a bleach stain on our dark clothes.