The two bricks in this photo have the same color, but the reflected color changes strongly depending on the orientation of the brick. The difference between the two photos is only that I rotated the left brick 180 degrees.
I do not believe that this was an intentional feature. I suspect the molecular structure of this part (with molecules that are somewhat aligned due to the material flow during molding) causes polarisation of the reflected light or absorption of certain polarised light orientations only, leading to a perceived color change. Looking at the parts through a circular polariser filter reduces the effect, but does not filter it out completely.
[Original post and comments on Flickr.]