All dyes came from plants, animals or minerals before William Perkin invented synthetic aniline dyes in 1856, according to Rajbir Singh in "Synthetic Dyes." People grew or harvested plants needed for dyeing. Examples are woad or indigo for blues, madder for red, weld for yellow and tree bark for brown. Chemicals called mordants bind dye to fabric and also modify the color. Some fruits and vegetables can give strong, lasting dyes. Often the color of the plant doesn't indicate what dye color will result.
Walnut hulls produce a brown dye. The color is permanent and will stain skin or anything else it touches. Whole fruits can be used, but the hull has most of the juglone, the active dye. Walnut dye is so strong that a mordant does not have to be used to get a good brown color. Intensity and shade of color is influenced by length of time in the dye bath, use of a mordant, and by the kind and age of walnuts gathered. Walnuts have been used as a hair dye, according to Mother Earth News.
Onion skins produce long-lasting dyes ranging from yellows, orange and brown for yellow-skinned onions to red-orange to dark tan for red-skinned onions. Variations in color depend on the type of mordant used. Unmordanted materials will accept onion skin dyes.
Strong reddish purple results from mulberries. Ripe fruits are put in water, then simmered with the material to be dyed. Alum and tin are the mordants. This makes a long-lasting, very color-fast dye.
Fresh ripe tomatoes give a reddish brown color to unmordanted wool or silk. When alum is used as a mordant, light yellow results. Color fastness is fair to good.
Beets give a reddish to rusty color at first, but the color fades with exposure to light. The red color from the the heirloom 'Bull's Blood' beet variety is the only red food coloring allowed in Sweden, according to the Missouri Botanical Garden website.
Crushed ripe blueberries, simmered with mordanted materials, give a dark reddish gray color. However, like the dye from beets, the color fades with exposure to light.
A fairly color-fast purplish blue color comes from ripe blackberries when alum is used as the mordant. It takes a quart of berries to dye four ounces of wool.
Use mature well-colored carrots. Simmer them with variously mordanted wools to give greenish yellow with alum and pale green with chrome and ammonia. The colors have good light fastness.