100% color accurate match without LUT

[nyalldawson]

It would be nice to remove the color LUT and determine exact CIELAB - > RGB conversion formulas matching those used by ESRI.

[mstuyts]

This gist I found shows one way of how to convert CIELAB -> RGB with python: https://gist.github.com/manojpandey/f5ece715132c572c80421febebaf66ae

I don't know if that's the way ESRI does the conversion.

[nyalldawson]

@mstuyts Thanks for the link! That's a similar way to what we currently do -- I originally started with the easyrgb formulas but found considerable difference in the results compared with ESRI's conversion. As a result SLYR currently uses a "refined" (hacked up?) version of these easyrgb conversion equations.