Are there expirations on color flow, glucose, glucerin etc? I haven't found a date on the bottles or cans.
What about gumpaste powder?

I'm just bumping ya, to see if anyone answers this, but I've had mine for along time, and they are still working good....I'm talking a year old.

Most likely these days yes. Does anyone pay attention to them NO!
I had cans of GumTex that must be over 25 yrs old. I still used them for adding to fondant.
I also had/have(?) a bottle of yellow paste color that must be some 30-50 yr old! The lable is sooooooo different/old looking I'm sure it is that old. It colors icing just fine; no smell, nothing different about how it works.

Just looking at my bottle of Wilton glycerine and nope no exp. date and none on any of my disco, luster or pearl dusts

None on the tylose powder either!