What does bottle black bottle black mean?

bottle black bottle black meaning in Urban Dictionary

noun. Used to relate to you with unnaturally black locks. The name comes from the reality that they dye their hair, apparently with something which came from a bottle.Can also be employed in a derogatory manner.The opposite of bottle blonde. (n.) somebody who has colored his or her locks black colored (see jar blond). The word arises from the truth that locks dye will come in bottles.