The prohibition of red women's clothes is well known, as is the definition of red in hilchos niddah. I hear many near-red garments being justified by calling them salmon, pink, purple, maroon, etc, but those colors would certainly be forbidden in hilchos niddah.*
What is the definition of red in regards to women's clothing?
* Black and dark brown are forbidden in hilchos niddah too, but obviously not in women's clothing.