There is nothing wrong with your script, I am sure of that.
My problem is that I cannot duplicate the transparent background on a third site. I’ve imported the .json file and still come up with the same black background that is listed in the title.
Here are the two working sites:
Period Drama
Genie Bohn
The site with problems is:
Look Back at Me.
Although, I cannot see it in the customizer, I have a transparent 20×20 png image in all three sites under “Content Images”.
I think I have deleted all relevant colors where this could becoming from. After a month of frustration, I am asking if you might know what I can try next – or I can set up an account for you.