The "Y" pattern on the front wing of these moths is well known.
What's probably not so well known is that the "Y" pattern is not composed of just differently colored scales, but rather differently structured scales.
I confess, I didn't know this either. I was just testing a new lens setup and used the moth wing because it's attractive. But when I looked at an "actual pixels" view, I couldn't make sense of what I saw. So I hauled out one of the "big guns", so to speak, and took a really close look. Here are the two pictures.
Canon 300D, Olympus 80mm f/4 bellows lens, full frame, stacked at 0.002".

Canon 300D, 10X NA 0.25 microscope objective, 50% of actual pixels, stacked at 0.00033".

At the higher magnification, we can see pretty clearly what's going on. The satin-textured "Y" mark is actually composed of many layers of individually almost transparent scales, lying very close together instead of coarsely shingled like the rest of the wing.
Hope you find this as interesting as I did!
--Rik