TT #91 · Parshas Tazria · Aliyah 1 · Passuk 4
English: But if it is a white discoloration on the skin of the body that does not appear to be deeper than the skin and the hair in it has not turned white, the priest shall isolate the affected person for seven days.
Chabad.org — Chumash, English translation + Rashi for Vayikra 13:4
Torah Temimah cites Shevuos 6b for the definition of baheres as the strongest white appearance.
E-Daf — Shevuos 6b · Shas.org · Sefaria — Shevuos 6b, source text and translation
English: “White” — it is white, and no other is white in this respect; hence baheres is strong white like snow.
Definition
The Gemara identifies baheres as the most intensely white of the four appearances, like snow; the other appearances are not white to the same degree.