Content (Position) Background
Among the JM templates, I like the large image format used in JM Deco but my preference is a white background for the Contents position. White text on white background strains the eyes. Moreover, one has less choices on what colors to use for text to make them easily readable in a black background. “White” background trumps anything else when there is a lot of text.
Framing. The Products list in JM Sulfur uses black text on white background. To minimize the glaring impact of differences in image sizes and text content for each product, one thing that could be done is to place borders to frame the image and text for each product. A good example of this is an old e-commerce template by GavickPro (in a salute to Joomlart, GavickPro uses the Joomlart T3 in their layout designs)
Cornelio