How to reproduce:
1. Create and open a new project
2. Install the Visual Effects Graph from the Pakcage Manager
3. In the Project tab, create a new Visual Effects Graph and open it
4. At the bottom of the “Output Particle“ Node, open the HDR Color Picker
5. Put in any three values into the RGB/HSV fields (i.e. 20-90-100 in HSV mode)
6. Keep the Visual Effects Graph open and select the Directional Light GameObject in the Hierarchy
7. Open the standard Color Picker in the Inspector > Light > Emission > Color
8. Put in the same values as in step 5
9. Observe the difference between the HDR Color Picker preview and the Standard Color Picker preview

Expected result: The previews show the same color
Actual result: The HDR color preview is a little brighter

Reproducible in: 2022.3.60f1, 6000.0.43f1, 6000.1.0b11, 6000.2.0a7

Reproduced on: Windows 11 Pro (24H2)
Not reproduced on: No other environment tested