How to set the lightness and brightness value right when changing the color of a paper texture?

If you just want to change the color, use a colored solid on top and change the blending mode to color. No point in messing around with dynamic adjustments.

Mylenium

The technique outlined is rather silly but to answer your question the numeric scale (-22) is Lstar so you need to be viewing Lab values. And you need a and b star values.

Let the output profile handle all this.

You seem (?) to want an Absolute Colorimetric conversion which will map paper white.