There is no CLIPS synthax hightlighting http://www.clipsrules.net/Documentation.html
See:
https://github.com/psicomante/CLIPS-sublime/tree/master/Syntaxes
https://marketplace.visualstudio.com/items?itemName=RickSladkey.CLIPSLanguageSupportforVisualStudio
https://groups.google.com/g/clipsesg/c/806KCCcd6rg?pli=1