Colored garments should not be laundered in the same water with the white clothes; they must be carefully treated to avoid fading or otherwise changing the colors. The treatment of delicate colors is too technical for this discussion; it requires an understanding of the chemical nature of dye materials to be able to prevent fading in some of them. Different substances, or mordants as they are called, are used to "set" or fix the colors so they will not fade. There are a number of chemicals used for this purpose, but they are not commonly applied in the home laundry.
Common table salt dissolved in water is often successfully used to set the color in a new wash garment before putting it through the regular laundry process. Colored clothes should be dried in the shade for if exposed to the bright sunlight while drying there is great danger of the color being faded.