More control on QSlider display properties

The QSlider components, in some styles (e.g. Fusion), has different background colors on the groove, usually indicating that the left part is "active". This may look good, but can also be misleading or convey wrong information. I'd like the option to disable this special coloring, having just a plain background as with other styles (e.g. Windows or Oxygen), and to set where the "starting point" should be (left, right, arbitrary inside position).

Use cases:

• A slider that goes from -10 to 0. I'd like the color to start from the right side.
• A slider that goes from -10 to 10. I'd like the color to start at 0.
• A slider that sets an orientation angle (or color hue) from 0 to 360. I'd like no color, since the 0 position is arbitrary and 360 = 0.