What a wonderful and detailed wrote up. Thank you for this! I wrote something similar but never released it due to not having a lot of hobby paint colors to include. It uses LAB for linear distance as a scoring mechanism and reflectance curves from RGB for the mixing. And a genetic algorithm for finding a recipe.
Here's a short video of an older version. Newer one let's you set how long to search for.
Here's a short video of an older version. Newer one let's you set how long to search for.
https://youtu.be/eGgrowt1fWg?si=NwucIgfpeWpbmCPX