Without color; lacking characteristics which give variety. blank (Adjective). Free from writing, printing, or marks; having an empty space to be filled in; as, blank paper; a blank check; a blank ballot. blank (Adjective). Without expression.
Yes they do damage hair. Every time I have tried one ,I wound up looking like a Q-tip or my head looked like cotton. A perm will damage even more and look worse if you have been coloring your hair. There's chance of it looking okay if you don't color your hair.
How soon after a perm can you color your hair? The process of cold wave perming basically exposes the hair to strong chemicals that break up the bonds, setting the hair to a desired style (either by curling or straightening) and then resetting the bonds back together.