Reproduction steps:
1. Open the attached “BugRepro” project
2. Open the “Assets/R16 Issue/SampleScene“ Scene
3. In the Game View, observe the bottom red texture

Expected result: The texture color transition is smooth with no banding effect
Actual result: The texture has a faint banding effect

Reproducible with: 2021.3.39f1, 2022.3.32f1, 6000.0.5f1

Reproducible on: Windows 11, macOS 14.4.1 (M1 Max)
Not reproducible on: No other environments tested

Note: In 2021.3.39f1, both the packed and unpacked textures have banding effect