My guess would be that the insides of the feathers are not even there at all. Select one of the feathers in illustrator and go to the “Object” menu, go near the bottom of the menu and you’ll see “Compound Path” in the submenu select the “Release”.
Compound paths allow “holes” to be created in solids. Say you have a logo you’d like to be able to place on any colored background. You would create a compound path so that the “holes” in the logo show the background color.
Just go into Illustrator and attempt to release the compound paths on all of the feathers (you probably will have to do each one individually) then take the inside path and color it different to see if it’s there.
Sorry able the ramble! This is my first attempt at helping someone.