How to reproduce:
1. Create a new 2D Template project
2. Create a new Square Sprite (Assets->Create->2D->Sprites->Square)
3. Observe the Sprite in the Preview window in the Inspector

Expected results: The Sprite doesn't have gray edges
Actual results: The Sprite has gray edges

Reproducible with: 2020.2.0a15, 2020.2.0f1, 2021.1.0a10
Not reproducible with: 2018.4.30f1, 2019.4.17f1, 2020.1.17f1, 2020.2.0a14

Notes:
- Unlike in 2020.2.0a14 and previously you cannot create Sprite Shapes without the package which disturbs the workflow for users who were used to it
- Additionally you cannot create Triangle, Diamond, and Polygon shapes like you used to
- In Unity 2020.2.0a15 and above to be able to create Sprites you will need to install the 2D Sprite package (comes pre-installed with 2D Template)