Swatch Thumbnails for CAS

Hello,

I apologize in advance if this is not the correct place to be posting this question.  I tried to create a new thread in the CAS and Pose Tutorials board, but I didn't see an option to do so.

I just created my first "recolor" of a clothing item in the Sims 4 base game.  The recolor was done by using a royalty-free image of a particular pattern, which I found on Pixabay. I am having trouble figuring out how to make swatch thumbnails in Sims 4 Studio, particularly since I would like for the swatch thumbnail to show the fabric pattern rather than a single (or two) color(s).  When I go in game, I can find my cc item in CAS and the game has generated a catalog thumbnail; however when I try to scroll over the different swatches for the item, the little boxes are grey.  I see information online about making the CAS catalog thumbnail, but not the swatch thumbnails.  This leads me to believe that there is something very basic that I don't fully understand.  In case it matters, the recolor was meant to be in addition to the clothing item in the Base Game (which only has one color), not instead of that one color.

Thanks in advance for any assistance.

PrincessImp

Edited to Add:  Okay, I have some ideas about what may be wrong.  The custom image I'm trying to use for the swatch is 32x32 pixels and a .png file.  Is there something wrong with that?  Do I need a different file type?  OR perhaps I don't know how to "move over" the custom image once I import it so that it appears in the first "swatch thumbnail" slot?  It's clearly not by right clicking and using the eye dropper tool...

Edited Again to Add:  I figured it out.  As you all are aware, you *don't* move the custom swatch thumbnail over.  You leave it and hit save.  Then, you move on to the next swatch.  Duh.  So sorry.