Along the body axis on the front of the head there is a slight concave groove which is a unique characteristic of this species. It is reported that the cleft becomes more prominent with age and that the skin within it pulses during vocalization. Risso's dolphins are strikingly coloured. Pale ochre-yellow highlights accentuate the muzzle. A white anchor-shape patch between the flippers resembles the chest chevron seen on pilot whales but is typically brighter and more extensive.
Calves become silver-grey, then darken to nearly black, retaining the ventral patches of white.
As animals age further, their heads, abdomens, and flanks lighten. One of the most striking characteristics of Risso's dolphins is the prominent scar pattern which criss-crosses the animals' bodies. These distinctive linear scars accumulate primarily on the animals' dorsal and lateral surfaces and have been hypothesized to result from the combined effects of lack of repigmentation of damaged tissue and a slower healing process than that observed in animals such as bottlenose dolphins. Measurements of scar widths and the distances between scars on several captive animals suggest that these marks are made by the teeth of other Risso's dolphins and squid. Less common are circular white scars located anywhere on the body, which have been attributed to bites of lampreys, cephalopods and cookie-cutter sharks, infestations of parasites and bacterial infections.