Reproduction steps:
1. Open the attached “IN-97763.zip” project
2. Open the “New Shader Graph.shadergraph” from the Project Window
3. In the “Color” Node click on the color bar
4. Observe that the Alpha value is 0
5. Observe the Alpha slider on the “Color” Node

Expected result: The Alpha slider is not visible on the color bar
Actual result: The Alpha slider is showing (a small white rectangle at the bottom left), suggesting that the value is greater than 0

Reproducible with: 2023.1.0a3, 6000.0.44f1, 6000.1.0b12, 6000.2.0a7
Not reproducible with: 2022.3.60f1, 2023.1.0a2

Reproduced on: macOS 15.3.2 (M1 Pro) , Windows 11
Not reproducible on: No other environment tested