Where Are Sierra's Grey Sidebar Icons?


In Mac OS Sierra, the icons in the Finder sidebar with just the normal view are light sepia. If one saves a file, the cutdown version of the Finder window shows grey icons in the sidebar. I know exactly where the sepia ones are, but the grey ones are not in the same place. Where are the grey sidebar images stored in Mac OS Sierra?
I see the finder sidebar icons are affected by the background, so you see the colors of whatever is in the desktop background, or other windows behind the finder window.
The "Save" window does not appear affected by transparency, so the sidebar icons are not affected.
So, I think the icons used in the sidebar for either window are the same icon images, and the transparency of finder windows makes those appear "sepia", but are not actually. You can show that by System Preferences/Accessibility pane, Display tab. Check "Reduce Transparency", and both finder and save windows icons will appear the same.
You are right! I had changed the background colour of the location of the those icons and they appeared sepia presumably because orange plus grey gives sepia. That brings up another question, however. I changed some of those icons to full colour opaque ones (that I got from a
Snow Leopard set) and that does not affect the grey icons that appear when I save a file. Why is that? Are those images also stored in a location other than /System/Library/CoreServices/CoreTypes.bundle/Contents/Resources?
I changed the sidebar generic folder icon from a light grey one to an opaque blue one, and saw that the folder icons in the Finder sidebar changed to a darker shade of grey. I think what happens is that there is a setting somewhere in Mac OS that changes everything in the sidebar to greyscale. Also, specially designed folders get changed to generic. Why do that in the first place, and where would those settings be in Mac OS?