occurs in a number of phases from the darkest "blue" birds to some very
pale individuals indeed and a mix of things in-between. This is one of
the commonest seabirds encountered in the North Sea and darker birds
are surprisingly regular even as far south as the southern Norwegian
This page presents some images of "intermediate" birds that are not
dark enough to warrant the term "Blue".
For pictures and information about Blue Fulmar see this page
and for more on "normal" Fulmars see this page.