The Bismarck had the white/black Baltic stripes added in several stages in early 1941 due to frost. By the start of the Baltic manoeuvres (March to May 1941) this was completed. The battleship at this time had stripes on both the upper hull and superstructure, dark grey areas at the bow and stern, plus false waves painted in white at the bow and stern.
The Bismarck left Gotenhafen on the 18th May 1941 and arrived at Grimstadfjord on the 21st Mat 1941. During this sailing (18th to 21st) the stripes on the superstructure were painted over. So, by the time the Bismarck dropped anchor in Grimstadjord in Norway, there were stripes on the hull only.
When the Bismarck left for the Atlantic these stripes, and the dark grey at the bow and stern, had been thinly painted over. But due to the thin paint the stripes and the dark grey at the bow/stern could be determined underneath. Sources disagree whether the false white bow wave was also painted over, or whether it was left in white.
The article by Daniel H. Jones at the website below suggests that the stripes were for identification rather than camouflage. He says: "Actually it appears that this painting style was a recognition marking and it was only used in the Baltic. Whenever fleet units based in the Baltic came out into the Atlantic the stripes were always painted out."
The article is at -
http://smmlonline.com/articles/kriegsmarinecamo/kreigsmarine.html
Cheers,
Dougie