Here is a sample of some of the rich colors produced by natural dyes. Such natural dyes would have been used exclusively in the uniforms of North and South, since these plant and mineral dyes were the only dyes available. Only a few synthetic dyes had been discovered by the 1860's. Unlike modern chemically dyed fabric, naturally dyed cloth will fade and change color as it is worn and exposed to sunlight. During the War, this fading produced much of what is referred to as "butternut"; the logwood and sumac dyes used on Southerners' gray uniforms soon faded to tan in the sunlight.
I dyed these wool jeans using black walnuts, sumac, alum, and iron. They have been piece-dyed and do not show the streaked pattern that you see in most wool jeans of today. During the war, fabric was dyed both ways -- sometimes before weaving (producing the streaked appearance), and sometimes after weaving (producing a solid, even color). Either way is period-correct.
Some of my garments are available in natural-dyed jean, either of my own making or from Ben Tart, who makes beautiful jeans using period recipes and dyeing methods. Prices for natural dyed fabrics are higher because the process of natural dyeing is quite time-consuming. Piece-dyed fabric must be made in vats or pots a few yards at a time.
