I'm working on a simple 2D RS pixel art style clone, and I would like to rip the map tile colors to generate 30x30 tiles. I'm just getting started with understanding the RS file formats and finding the right tools for this task. I found a tool called OpenRS that I think may do the job.

-Correct me if I'm wrong, but what I would want to do is pull all the underlayIds? The overlayId's are just for roads and water and stuff?
-Which cache index contains this data?

Appreciate the help, been doing some searching on this site and it's tough to find a general overview of the cache system and dumping the data.