Closing, as this Unity version will no longer be getting updates.
Different implementation of color correction in this version, fix can't be safely backported
How to reproduce:
1. Open the “TrailColor“ project
2. Navigate to the “Edit > Project Settings > Player“
3. Expand Other Settings
4. Set Color Space to Linear
5. Select the “Particle System“ GameObject in the Hierarchy window
6. Observe the Game view
Expected result: The color of the particles and the Trails are the same
Actual result: The color of the Trails is lighter than the particles