Check out #6, it’s all about settings — how to test, suggested settings for various materials, and general advice about what they do.
Also with tile it’s also about technique, there are lots of posts about how to color your engraves. Searching for “Tile engrave in:first #\glowforge-project-examples” will show you all threads about tile engraving projects posted in made on a Glowforge
https://community.glowforge.com/search?q=Tile%20engrave%20in%3Afirst%20%23glowforge-project-examples
Lots of those threads get into specifics about process which is the real gold.