Self-striping variegated yarn is frequently used in sock knitting
Variegated yarn is yarn dyed with more than one colour. It can produce effects that vary depending on the technique of the crafter, the pattern used, and the frequency of colour change. These effects include "flashing" (lightning-bolt effects) and "pooling" (patchy or marbleized effects). Some yarns (known as "self-striping yarns") are designed to produce stripes when used to knit small items such as socks or mittens.
This lace stole is being knitted from variegated laceweight wool