Line thickness, style and color are grayed out in the sketch environment
Solution This normally happens when the option "Relationship Colors" is on in the Sketch environment. The option can be found in the Inspect tab> Evaluate group. Turning it off allows the sketch color, style and thickness to be available again.
The reason for this is that when the option is on, fully constrained elements' color is changed to black, so we do not want you to override that behavior by manually changing color, style or thickness of the black
constrained sketch elements.
Notes and References
Hardware/Software Configuration Platform: INTL64
OS Version: 764SP1