The blocks in the inventory are shaded wrongly / are not lit enough, in comparison with 1.14.4. This can sometimes lead to confusion of blocks, especially in terms of colors (accessibility).
Here are (only) a few obvious examples:
MC-167317 Blocks rendered darker than before in inventory
MC-167560 The blocks in the inventory are not lit enough on their top
MC-193648 Banner item's shading is incorrect/too dark in inventory
MC-167070 Shields in inventory are too bright
MC-162518 Blocks in the inventory are no longer shaded properly