System Information
Operating system: Linux-5.0.0-31-generic-x86_64-with-debian-buster-sid 64 Bits
Graphics card: GeForce GTX 750/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 435.21

Blender Version
Broken: version: 2.81 (sub 13), branch: master, commit date: 2019-10-04 17:11, hash: rB5287eaac5b09
Worked: (optional)

Short description of error
[Please fill out a short description of the error here]

Exact steps for others to reproduce the error

1. Open Blender
2. Open Preferences
3. Go to... Themes -> User Interface -> Icon Colors -> File Folders
4. Change Color
5. Save Preferences
6. Restart Blender

Color is back to the default color.