Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: Quadro M4000M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 425.45
Broken: version: 2.81 (sub 8), branch: master, commit date: 2019-09-06 13:07, hash: rBa94bf0e1349b
Broken: version: 2.80 (sub 75), branch: master, commit date: 2019-07-29 14:47, hash: rBf6cb5f54494e
Broken: version: 2.79 (sub 0), branch: master, commit date: 2018-03-22 14:10, hash: f4dc9f9d68b
I just found there is some inconsistencies of curve handle colors between UI and user manual.
I've checked the colors in theme preferences, screenshot as below:
I tried to reload the factory settings, but it didn't work.
I've checked this in blenderCN community, some display correctly as theme settings, and some can reproduce it.
I believe there is an bug here, and hope this will be fixed.