It is identified as a glaucoides Iceland Gull despite some shadowing in the primaries. Although stippled, the pattern of pale and dark in the primaries is not matching that of a classic Kumlien’s Gull as the faint dark shading on the outer webs of the outer primaries is broken before reaching the very tip even though there are some distal pigmentation.
Note that it is not abnormal for 2nd- and, especially, 3rd-cycle glaucoides to show a brown wash on the outer primaries. The plumage of these immature gulls often looks quite retarded, with still lots of brown in the wing. Note that the brown wash on outer primaries of such birds simply matches the brown wash on outer secondaries, as is often the case in other 3rd-cycle gulls (e.g. Herring Gull). It is just a trait of immature plumage.