TT #102 · Parshas Tazria · Aliyah 2 · Passuk 7
English: However, if the mispachath spreads on the skin after it has been shown to the kohen for its purification, it shall be shown to the kohen a second time.
Chabad.org — Chumash, English translation + Rashi for Vayikra 13:7
Torah Temimah cites Sifra (Toras Kohanim) for spreading in an appearance different from the original one.
Sifra — Vayikra 13, Midrash Sefer
English: “If it spreads further”—I know only spreading in the same appearance. From where do we include spreading in a different appearance? Scripture repeats “spread,” extending the rule to any qualifying spread.
Textual derivation
Spreading can count even when the new area does not share the original lesion’s exact appearance; it is not limited to spread in the original shade.