Closely relates to MC-74408 and MC-265038.

The bug

In 23w31a, the lapis lazuli outline was removed from the enchanting table UI texture file due to it being handled as its own texture (textures/item/empty_slot_lapis_lazuli.png) as per MC-259401. However, this change did not apply to Programmer Art: unlike in the current vanilla textures, the lapis lazuli outline is still baked into the UI texture. As a result, the new lapis lazuli outline texture is overlaid on the old one, making it look different from how it did before 23w31a (and also causing MC-265033 specifically in Programmer Art as a result).

An extension of this issue is that the lapis lazuli texture visible in the smithing table uses the new outline texture even when Programmer Art is in use.

How to fix

The file "textures/gui/container/enchanting_table.png" should be deleted from the Programmer Art textures - the only difference between it and the current textures is the presence of this outline, which should not be present on the UI texture to begin with. It can fall back to the current vanilla version without any issues.

Programmer Art instead needs the file "textures/item/empty_slot_lapis_lazuli.png" to be replaced with the old enchanting table lapis lazuli outline texture. I've attached this texture extracted from the old UI texture, so all that needs done is for it to be implemented into the Programmer Art resource pack accordingly to fix this issue.