Inside a home it's CPVC, which is off white.
PVC can only be used outside, typically underground.
I've seen yellow glue for CPVC.
I've discovered that the prior owner of my new house did a lot of work himself, and not all of it is well done. Since I know a bit more about electrical work, I have a pretty good sense of some of the things I'll need to re-do. With plumbing I'm not too sure. The home inspector pointed out a couple of things, but I noticed that the PVC pipes he put in all have yellow cement on them. I'm used to seeing the purple primer stain on the pipe. Did he use the right stuff?
I just went downstairs and took a look. The supply pipes are all, as you said, CPVC. The waste lines, however, are PVC, and they also have the same yellow cement.
CPVC cement can typically be used on PVC, but not the other way around. Because the CPVC cement is stronger, it may take a bit longer for the PVC joint to harden up, but it will still work. Some inspectors like to see the purple cleaner, but that comes in clear as well.
Important note - I'm not a pro
Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014
There are differences in the glue's chemical make up and how they should be used. CPVC glue will not solvent weld and bond to PVC. It may stick for a long time, but will eventually leak through. Just like the universal cpvc,pvc, and abs glue sold at big box stores. There is really no such thing as a universal or cross-material glue.
In my own experiences I have repaired many leaks that were caused by transition glues and universal glues done by home owners and handymen....even some plumbers.
Look where some of the deception starts. You can go to some big box and hardware stores that show on the aisles "PVC and Black PVC Pipe" and stock mostly universal glue to control inventory.
quote; then it is deceptive.
1. Transition glues are not approved by most codes
2. Most transition glues specify they are not for pressure systems.
3. The gas utility companies are NOT under "most codes"3
4. Our utility company ALWAYS used a "standard green" transition glue to join their ABS and PVC high pressure gas lines.
5. So that pretty much destroys any arguments about transition glues, at least until something blows up, which has not happened so far.
Licensed residential and commercial plumber