Thank you for your question.
The best approach is to use the css class of the content block, you'd like to apply background color to. You can find it in Advanced
options in the editing panel of your content block. The name of the class by default is sfContentBlock, but you are allowed to modify it. After you have the css class, simply include this sample to a css widget on your page:
If you have several content blocks on your page, make sure to give them different class names and add similar code for each of them in your css widget.
Let me know if you have any additional questions.
the Telerik team
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Public Issue Tracking
system and vote to affect the priority of the items