NVIDIA Control Panel - Color Correction - How to translate the relative correction values to absolut

The nvidia settings tool on Windows/Linux offers color correction capabilities.

However, I could not found a explanation how to translate the relative values (-1 to 1) to absolute RGB values.

In the preview color curves, I can see it is a simple addition of a constant value. Experimentally, I found that the value 1 for example results roughly in a change of 70 in a range of 0 to 255 rgb.

Is there a official documentation on that matter? This would be very great because i cannot 100% trust my experiment and specific values would be very helpful.