rufescent
Becoming reddish; tinged with red.
The more inland, lighter race is distinguished from A. u. uropygialis in being much paler on the back, by the edgings of the forehead scallopings and auriculars being paler, and by having the brown of the forehead less deep and less rufescent.
Where it comes from
Circa 1820, from Latin rufescens, present participle of rufescere (“to become reddish”), from rufus (“red”).
Adapted from the Wiktionary entry rufescent (CC BY-SA 4.0).