Lewis & Short

pallesco, pallăi, 3, v. inch. n. [palleo], to grow or turn pale.

  1. I. Lit.: ut qui timent sanguine ex ore decedente pallescant, Gell. 19, 4, 4: pallescere curis, Prop. 1, 13, 7: nullā pallescere culpā, Hor. Ep. 1, 1, 61: pallescet super his, will turn pale with emotion, id. A. P. 429: umbraticā vitā pallescere, Quint. 1, 2, 18; 12, 10, 76.
  2. II. Transf., to turn pale, sallow: pallescunt frondes, wither, fade, Ov. A. A. 3, 704: viso pallescit flamma veneno, Val. Fl. 7, 586; Plin. 9, 17, 30, § 66.