What does it mean to set comparative color and tone LAB?

Question

Adobe Photoshop

There is a technical task in which the last paragraph says
- Yellow gold Comparative color and tone LAB: L - 92, A - 1, B -24,
please tell me how to work with these values? If I expose it in curves, it turns out some kind of dregs (too dark a picture is obtained), but most likely I’m setting it wrong.

Answer 1

Apparently, by "Comparative color" one of the blending modes of Photoshop was meant. Which one - only the one who translated the photoshop of the author of the TK and, possibly, the one who sold the grass to the translator, knows.
If you know roughly what should happen, try choosing a blending mode. Most likely, something from the Difference / Exclusion / Substract / Divide group. But in general, for such TK, the author needs to hurt.

Answer 2

Looks like you're applying for a job as a retoucher? :)
Watch the video https://www.youtube.com/watch?v=Cg-ZImzXoDk
You need to paint the discolored metal with a color sample using the Color Replacement brush