It is quite noticeable when you are using a limited selection of tiles or image has desaturated colors.

I've done some similar work[1], but issue with L*ab color is it's terrifically slow to calculate diff, at least in JS.

[1] https://imgur.com/a/g3EzcSV

there is no perfect way to measure color distances, mostly because it needs to account for human perception of color and there are individual differences in color perception among people.