"Hard to follow" is itself hard to follow. The shades and colors and hard lines made it difficult for German stereo rangefinders to lock on, it made it difficult for submarines to determine the shape and length which were necessary for proper range, speed, and angle estimates, and in general it made target identification slower and more uncertain.
It wasn't zebra striping either. It was bizarre blocky shapes, always with straight edges, and there was a lot of color. The reason so many people think it black and white is because color film was very expensive and rare, and newspapers didn't print color pictures.