I have a need to create an alternate grayscale palette for all room pics for Zork (100+). Similar to day/night scenes I've seen done in SCI0, I'm guessing there have been similar scenes in later Sierra games. I could create 2x the number of pic resources, but it seems like using an alternate palette for existing pics would be appropriate. I'm thinking of taking each existing palette and converting it to grayscale in a non-manual way?
Any suggestions how best to accomplish what I'm trying to do?