On creating the Particle System effect, It is not rendering correctly in Scene view & On changing Particle colors their resulting reflection not appearing in the Scene view.
On changing Particle colors their resulting intended reflection appearing in the Game view, Refer attached video.

Steps to repro:
1. Create a New Project
2. Hierarchy > Effects > Particle System
3. Observe Scene view
also
4. Try to change Inspector > Particle System > Start Colour
and observe its reflection in Scene View.

Actual result:
Particle System is not rendering properly in the Scene view.

Expected result:
Particle System should be rendered properly in the Scene view.

Reproducible in:
2021.2.0a6, 2021.2.0a5, 2021.1.0b8.

Working Fine in:
2021.2.0a4, 2021.1.0b7, 2020.2.6f1, 2020.1.17f1, 2019.4.21f1

Environment:
Occurring on Windows 10 & macOS 10.15.