Ok. I'm still a newb with DAZ..But where do I find the "Diffuse texture" of a character? Like what's the file usually named or look like?
Textures are mostly commonly JPG's, although they can be PNG's as well. Mostly commonly, they're buried in the "data" or "Runtime" folders in your DAZ content area.
You'll want to look on the "Surfaces" pane. Each surface can have its own texture, so you first have to select an object (1) then select a surface (2). Then look for "Base Color." (3)
A surface can have a fixed base color (specified by the three numbers) or it can have a texture applied, in which case you select it with the pull-down arrow just to the left of the numbers. (If you do both, the color "tints" the texture.)
If there's an existing texture attached, you can hover over the pulldown (which will actually look like a tiny version of the image) and it will show you a slightly larger version and also show you the path to it.
You can change the texture by clicking there and then either selecting something from the list presented, or selecting "browse" to go looking for a file.