Bizarre. I right clicked on model, chose a new color, not the same green, and instantly it worked.
Just needed some kind of a refresh?
Sorry for the bother. I worked on this for hours without success before I posted the question. Hopefully this helps someone who is doing everything right, knows how things work, but not getting expected results.
EDIT: coming back to this an hour later. I don’t think it was a refresh of the color palette. I think I had unchecked the 'strength pressure" icon while I was changing colors. The unchecked is what I believe made it finally paint. I believe this because I went back to the file and couldn’t reproduce the “solution” that happened when I changed the palette color. I think what I actually did was uncheck ‘strength pressure’ which, for whatever reason, allowed me to paint on my model. I’m using a Wacom tablet if that matters.
That still doesn’t explain these weird patterns when I was just trying tp paint a solid texture on my object. In other words, I was able to finally paint on the object but it either paints solid black if I have solid black chosen or these weird designs if I have any other color chosen. However, if I change the texture type to anything other than “image”, technically called “image or movie”, anything other than that like blend, noise, clouds, etc…works as expected.
Weird patterns when painting a solid color on top of an image texture. Maybe i need ‘udims’ or something else but that solution is a mystery now.
Weird patterns: That’s just from painting blue, green, etc… on a red texture image, as strange as that seems.