If I find two paint colors from different brands and they have the same LRV value and RGB values, does that mean the colors are the same?

Goodness gracious absolutely not. No, no, no. Just reading that gave me hives. 🤣

LRV - really isn't all that impressive. Other data values are far more useful.

Because LRV is just a measurement of how much light a color reflects. It doesn't directly speak to what a color looks like. The only two attributes that tell you - directly - how light or dark a color looks is L* from the CIELAB/LCh color space and Munsell Value.

So an "L" or the word Value answers the question how light or dark does a color look.

Munsell was the template for CIELAB/LCh. So both model human color perception, both are perceptually uniform, both have notations that are human readable because they are mapped to the way we see color in 3 dimensions: hue, value and chroma.

RGB is none of the above.

It's ONLY function is to mimic in real life color digitally. And it's ill-defined even for that purpose. RGB values are not human-readable nor do they define or describe color appearance. E.g. RGB doesn't indicate how much red, green or blue a "color has in it".

The RGB color space is obsolete and being replaced with OKLCh values.

No one is going to miss it. Developers made the switch immediately.

As of May 2023 Chroma, Firefox, Safari (and a couple other ones) recognize OKLCh to replace RGB.

OKLCh is basically next-gen CIELAB/LCh with an additional attribute "a" which means you can also control transparency.

All that's good news -and, of course, there's a lot more that could be said about all of it.

But how color shows up on your device will forever and always just be a digitized attempt to mimic color in real life.

The only data values that can be used to compare what colors look like to a human with normal color vision are:

L = Lightness

C = Chroma

h = Hue Angle

Or Munsell Hue/Value/Chroma