Rick -re your comment - Why not allow someone to use a graphic that is being used to describe a course? Then these graphics would really become meaningful. You can- that is the main point of the course images. If you have a course graphic then it appears. You only get the patterns if you don't have a course description graphic. See
3.5 Course Overview Block Banner Colors
Yep, I now see! Well, this opens up a lot of possibilities.
Do you know if there is any recommended aspect ratio for these course graphics, or pixel size?
I had this same question-I did some screenshots and measurements of the banners and got about 600x150 for the banners. If one were to make their own, it would need to roughly be this dimension- I don't know about adding text or anything and it being centered or not.I wanted to assign the same color to the same type of course in our setting (4 same courses across 5 cohort levels). This can be easier to say "click to the purple one" instead of name since our students are also EFL students. Below, these aren't randomly generated-rather I made banner images out of the randomly generated designs in a test installation and assigned them as course photos this way until/if the color picker gets added .