I call him Joseph

Our local hermit crabs, the Hairies, Pagurus hirsutiusculus, are usually a drab greenish-brownish-greyish mud colour. It's a mask; they're wearing a coating of algae, mud, leftover grunge, and sometimes a few barnacles. Underneath all that, they're a pale green, with blue knees and white patches on the legs. The body, of course, is hidden by the borrowed shell.

When they're freshly molted, and haven't had a chance to muddy themselves up yet, the true colours shine through. I caught one a few minutes after a molt, hanging out on the seaweed right in front of the wall, without a shell, showing off his coat of many colours.

Red, orange, yellow, green, blue, indigo, violet; all the colours of the rainbow.

The photo is fuzzy; the seaweed is swaying, the glass wall algae-coated. But the colours shine through.

Hairy hermit, as found on the shore, in his normal coating of mud and algae.

(Title from the Biblical story of Joseph.)