Kolbeinstangi is certainly not the standard cylindrical design. Here's what UNC has to say:
"1942. Active; focal plane 24 m (79 ft); one long (2 s) flash every 10 s, white, red or green depending on direction. 19 m (62 ft) square cylindrical concrete tower with lantern and gallery. The design of the building makes it appear at a distance to have one or more black vertical stripes on each face. This is the leading light for the village of Vopnafjörður, located about 2 km (1.2 mi) northeast of the town."Where's Vopnafjörður? Click here. (Google Map link) It's almost exactly on the other side of Iceland from Reykjavik. (Don't bother with Google's satellite image; it's socked in with clouds.
This is the only other picture I could find other than the one on the UNC Lighthouses site.