Quite correct Stein, the decks were green... well, on Sagafjord and Vistafjord.
Sorry about the small photo. Not that great, but does show the foredeck as Green.
My two little 1200 scale models of these two ships also shown the steel decks were painted Green.
I was in port and a NAL (cargo boat) ship was lying in the adjacent berth. The crew had painted the grey hull and the bootopping was done as well. I real mess! All of that white stripe was covered with paint. I thought it would take an age to repaint it. Not long after that I looked again and the strip was completely done! I took around the dock to have a look. That strip... and same on the Sagajord and Vistfjord has a 1/2 inch plate x 4 inch width, welded along the hull. With a small roller it would be done in minutes.