Sumatran & Malaysian red bloods, P. c. brongersmai
Borneo short tails (a.k.a. Borneo bloods), P. c. breitensteini
Sumatran short tails (a.k.a. black bloods), P. c. curtus
The main differences are color and head shape. Borneos and Sumatrans are, on average, a tad smaller and more docile than red bloods. Bloods are dark red in color, Borneos are much lighter, peachy colored, and Sumatrans are black and silver. There are also differences in head shape, but I'm not exactly sure of the specifics.