Calliostoma tricolor, common name the three-coloured top shell, is a species of sea snail, a marine gastropod mollusk in the family Calliostomatidae.

The surface is cut into a finely densely granulated pattern by the decussation of numerous spiral striae with close, regular, impressed lines of increment.

The base of the shell is slightly convex, encircled by numerous unequal lirae.

and backed by a curved purple streak, which is encircled by a band of bright light yellow.

[3][4][5] This species occurs subtidally from San Francisco, California to San Martin Island, in northern Baja California, and is found offshore from 16 to 70 meters.