This repo contains the shader code for applying a LUT in the material to any RGB color. It was made and tested on Blender version 3.5.
If you want a top level explaination of how the stuff are made, you can read my blog post here: https://medium.com/@shahriyarshahrabi/day-night-cycle-using-lut-in-fragment-shader-of-materials-80edaf26f655
================= Everything is in the a node group. The node group takes a color and applies the LUT to it. If you click on the main object, and look at its material you will see both the nodes and the rest of the setup. If you press Space or play, you will see the animation play out which is you can see in the GIF