These sea-run fish are silvery with an olive-green to brown color on the back and numerous red to orange spots on their sides. Young Dolly Varden have about eight to ten wide, dark parr marks or oval blotches which contrast with the mottled olive-brown color of their body. The mature males become brilliant red on the lower body surface and the lower fins become reddish-black with white along the leading edges. Mature females are similar but are less brightly colored. Compared to Bull Trout, Dolly Varden's heads are more blunt, bodies are more oval and trout-like, somewhat shorter upper jaws which are more straight, and smaller and more crowded spots on dorsal surfaces.