Operating system: Windows-7-6.1.7601-SP1 64 Bits
Graphics card: GeForce GTX 1060 6GB/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 419.35
Broken: version: 2.80 (sub 58), branch: blender2.7, commit date: 2019-04-24 02:30, hash: rB1b839e85e142
Short description of error
[Please fill out a short description of the error here]
The color prop in the Brushes panel in the tools tab in Properties editor is greyed out for the grease pencil object in draw mode. And so not editable. The same prop in the topbar is functional.
And here you can change the color.
Exact steps for others to reproduce the error
[Please describe the exact steps needed to reproduce the issue]
[Based on the default startup or an attached .blend file (as simple as possible)]
Open Blender, create grease pencil object, switch to Draw mode. Have a look into the brush panel in the properties editor in the tools tab.