Is it normal for black pants to produce red water when washed?

Yes, it is normal. Black color is composed of three basic colors: red, yellow, and blue. Red color usually has poor color fastness, which means it tends to fade easily. Therefore, when washing clothes, you may notice the water turning red. Similarly, if the color fastness of yellow is poor, the water may turn yellow.

What causes black pants to turn red?

Black color is mainly composed of red and blue colors. During washing and bleaching, the color gradually fades, and the original blue color is washed away, leaving only red. The mixture of the three primary colors of pigments, also known as subtractive mixing, results in a decrease in light. The combined color emits less light than the original colors. The more colors are combined, the more light is absorbed, and the color becomes closer to black. Therefore, black clothes usually have a tint of red or blue.