Hi Peter!
Thank you so much for the lesson in css3.
I had to repeat the pattern so I did this:

1. in the color section I defined no image and just defined an ID
2. in CSS I wrote:
#color-section ID {
background-image: url(../pattern.png) , url(../background.png) ;
background-repeat: repeat, no-repeat;
background-size: auto,cover;
}

and it works like a charm!
Thanks a lot!
Great Theme! Great support!
best,
Chris