A recommendation is to stand 6 or 10 foot away and see if the signage looks okay. That is a thing with signs. We are looking at them right there in our lap, but others will be a distance away.
As to parameters:
I use a lot of the two color for earrings and signs and have some real accurate ‘ballpark’ numbers for it.
Engrave – 1000/60 @195 0.060
Score – 300/15 0.060
Cut – 225/100 0.060 (if seems to not quite cut – try 225/full).
Some colors like teals, some blues, and especially red seem to need a harder hit because it blocks or absorbs the laser.
I have had to drop speed to 800./80 or 500/100 for an engrave in one pass on particular colors.
Experimentation is the key. For instance, the red/white debris seems to almost act like a dye pack and tints the exposed white engrave. A normal engrave of 1000/60 followed by a low power ‘clean up’ second pass will resolve this coloration problem.
These numbers are my go to start parameters, but as mentioned, sometimes they may need a little nudge.