Plucking gray hair does not make more grow in its place. That is a common myth, simply because only one hair is capable of growing out of one hair follicle. At most, just one other gray hair may grow back.
At the first sign of a gray hair, one's first instinct may be to pluck it. Hesitation sets in, however, because of the belief that every time a gray hair is plucked, multiple hairs grow back in its place. This myth, however, is completely false.
Only one strand of hair can grow per hair follicle. Therefore, when a hair is plucked from the follicle, whether it is gray or not, only one hair grows back in its place. Gray hair begins to show when the pigment cells in the follicle die. This causes hair to lose its color and turn gray. Plucking the hair will not cause surrounding hair strands to turn grey, this will happen naturally.
It is possible, however, for the new strand of hair that grows back is of a different shade of gray than the one that was plucked. This is because the pigmentation differs slightly and is not totally consistent with different strands of hair. Also, if hair is plucked consistently from the same follicle, there is a chance of damage to the follicle. This may mean that eventually no hair will be able to grow from that particular follicle.