C. MACKPRANG JR.
image by Klaus-Michael Schneider, 8 Apr 2009; observation 15 October 2008
image by Klaus-Michael Schneider, 8 Apr 2009
M289 is celestial blue with a white diamond bearing red M. Schneider observed the flag at the Hamburg building on 15 October 2008. The Esso/Schornsteine sources support a lighter blue, though perhaps not as pale as the FOTW rendering.
M691 is the darker-blue version based on a photograph of Bühne’s table flag. The website’s flag logo and Mackprang Holding banner also support darker blue, while another logo uses two shades.