See bug#47574 for a self-contained explanation.
That's about the 'match' face. I thought you were asking about xref
and project.el, I guess I was confused.
The colors you suggest seem okay to me, with a possible exception of
lemon chiffon, but I only tried them on the default light background.
'xref-match' face is customizable separately, but I don't think it will
be productive to change only it but not 'match'.
The faces are used similarly enough, so it's hard to justify making them
look different in the default configuration.
I'm not sure I agree with "used similarly". Are you talking ab out
the faces in the XREF buffer? If so, they don't show matches within
context of a source line, they show symbols.