Pages and dashboard would look better and sections would be more clear if the background of the entire content block was a different color as opposed to just the top strip.
Thanks for your idea. Mosaics can be really nice, and we have started using that in our latest company design.
When it comes to content blocks we will stick to white background, because it is - for most people - easiest to read text on white background. However, we are revamping the user experience across the product over the next year and we are looking at different styles. So watch this space.