Cary L. Brown,
Yeah depends on the angle you look at the grilles at. From the top they're purplish, from the front/bottom they're pinkish purple, from level they're blue
Did you know the reason for that? This is anecdotal... ie, I can't give a source, I just remember reading it SOMEPLACE. But I'm confident, even if I'm not able to provide my source, that the source was legit.
There's a die used in inspection of aluminum castings which is purple in color. The inboard and outboard grills of the nacelles were made from machined aluminum, and were treated with this. I believe that the "slot fill" clear material (probably plexiglass) was in-place at the time, and the whole thing was coated, internally, with this inspection dye.
Here's a source to look up the actual process I'm referring to.
And in this one, you can actually see the color of the dye in image #5.