How to reproduce:
1. Create a new project and install URP via Package Manager
2. Right-click in Project Browser > Create > Rendering > Universal Render Pipeline > Pipeline Asset
3. Edit > Project Settings > Graphics > Select RenderPipelineAsset > UniversalRenderPipelineAsset
4. Select the Main Camera in the Hierarchy
5. Change Background Type to Solid Color in the Inspector

Expected result: Game View is not overlayed by Camera's component Solid Color background
Actual result: Game View is overlayed by Camera's component Solid Color background

Reproducible with: 7.1.1 (2019.3.0b4, 2020.1.0a19), 7.1.7(2019.3.0f4, 2020.1.0a19)
Not reproducible with: 4.10.0(2018.4.15f1) 6.9.0, 6.9.2(2019.2.18f1), 7.0.0(2019.3.0a12), 7.0.1(2019.3.0b12, 2020.1.0a11)
Could not test: 2017.4.36f1 Package Manager is not introduced

Notes:
- More information and screenshot of actual result attached in Edit
- Not reproducible on Windows(DirecX11, OpenGLCore, Vulkan)
- Tested macOS 10.13.6, 10.15.2
- Reproducible on macOS (Metal, OpenGLCore)
- Not reproducible if a new URP project created via Hub