How to reproduce:

1. Open the “VertexColorBug.zip” project
2. Open the “SampleScene”
3. Select the "Square" GameObject in the Hierarchy
4. Select any color in the Inspector
5. Enter the Play Mode
6. Observe the Game view
7. Exit the Play Mode
8. Select any color in the Inspector
9. Observe the Game view

Expected results: The selected color is used in Play Mode and is editable after exiting the Play Mode
Actual results: The color becomes fixed to white when in Play Mode and is not editable after exiting the Play Mode

Reproducible in: 2023.3.0b1
Couldn’t test in: 2021.3.33f1, 2022.3.16f1, 2023.2.4f1 (No “Disable Color Tint“ option in Graph Inspector in Shader Graph Editor)

Reproduced on: Windows 11 Pro
Not reproduced on: No other environment tested

Workaround: Save the Shader Graph Editor screen

Note: The issue appeared when the option to “Disable Color Tint“ was released