The bug
The translucent white effect displayed in the inventory when an item is in a disabled state (recently thrown ender pearl or wind charge, recently eaten chorus fruit or disabled shield) cannot have its texture changed, and seems as though it may be hardcoded.
How to fix
Introduce a texture file for this effect (a translucent white square should suffice).
Linked issues
relates to 30
MC-278413
Chat background cannot be retextured
Open
MC-166809
Cooldown rendering stutters while pausing
Resolved
MC-264571
Both standing and wall sign GUI backgrounds cannot be retextured independantly from the block
Resolved
MC-268805
panorama_overlay.png no longer works
Resolved
MC-268927
The dark background in inventory screens cannot be changed via resource packs
Resolved
25 more links
I don't really think this is a bug but rather a problem. Also relates to MC-270257