The Collaborative International Dictionary of English v.0.48:

Pintos \Pin"tos\, n. pl.; sing. Pinto. [Sp., painted,
   mottled.] (Eyhnol.)
   A mountain tribe of Mexican Indians living near Acapulco.
   They are remarkable for having the dark skin of the face
   irregularly spotted with white. Called also speckled
   Indians.
   [1913 Webster]