Select a mesh that has the Physique modifier applied to it. > Modify panel > Tendons sub-object level > Tendons rollout > Display group > Click Display Options.
This dialog lets you customize how Physique displays tendons at the Tendons sub-object level.

Tendon Cross Sections—The check box toggles the display of tendon cross sections. Default=on.
Click the color swatch to change the color of tendon cross sections displayed in viewports.
Tendon Attach Points—The check box toggles the display of tendon attach points. Default=on.
Click the color swatch to change the color of attach points displayed in viewports.
Tendon Attached Links—The check box toggles the display of attached links. Default=on.
Click the color swatch to change the color of attached links displayed in viewports.