photshop plugin -- 2

need a photoshop plug that takes a layer and applies a new color mapping on it (about 3000 new colors so cant use builtin colour mapping) and saves it in a new layer. prefer uxp front end since cep is deprecated. note the images this will be used on are 100mpixel so C++ will be essential. will provide a hash table for the mapping in C++ or required format. it needs to work on mac and windows