Parashas Metzora · Passuk 14:04
Chabad.org — English translation + Rashi
Torah Temima points to Yerushalmi Kilayim 9:1.
English: “And crimson wool” — just as the crimson wool comes from a living creature, so too any dye derived from a living source is included.
Heqesh / comparison
Chazal extend the rule of crimson wool to other dyes that originate from living creatures.