Lightroom’s HSL/Color Mixer hue sliders are not direct “degrees of hue rotation.” They are a relative remapping of a selected color range toward its neighboring hues on Lightroom’s color wheel.

For example, the red slider pushes reds toward the adjacent colors: one direction toward magenta, the other toward yellow. Likewise, blue shifts toward cyan on one side and magenta on the other. So ±100 means “move this color family as far as Lightroom allows toward the neighboring hue,” not “rotate exactly N degrees.”

That also explains why the result can look asymmetric:

• each color channel sits between different neighboring hues,
• the available range on each side is defined by Lightroom’s internal color mapping, not a fixed angular amount,
• and real measurements can vary depending on how the resulting color is being read or converted in other software.

In short, the slider scale is an editing control, not a calibrated hue-degree scale. Equal positive and negative slider values are meant to produce comparable relative shifts within Lightroom’s color model, not identical numerical hue changes in degrees.