The Science of Hairballs - Why Do They Form? Friction and tangling are the causes of hairballs

When cashmere is dyed as a yarn, the color of the dye comes out straight away. This is called "solid dyeing" in the industry, and solid dyeing tends to produce simple colors.
Each color of cashmere products may appear to be a single color, but to actually produce that color, five to six slightly different colors of wadding are blended to make that colored wadding and spun. Of course, the amount of yarn for each color is different, and it takes a lot of time and effort to dye many colors.

When you look at a sweater under a microscope, you can see that there are fibers of slightly different colors mixed together.
I was thrilled when I found blue in the top gray color.