TT #155 · Parshas Tazria · Aliyah 3 · Passuk 19
English: If, at the place of the boil, there is a white swelling or a bright reddish-white spot, it shall be shown to the priest.
Chabad.org — Chumash, English translation + Rashi for Vayikra 13:19
Sifra (Toras Kohanim).
Sifra — Vayikra 13, Midrash Sefer
English: The reddish-white bright spot can establish the qualifying mixed appearance.
Textual derivation
The verse includes a mixed reddish-white appearance among the qualifying forms.