It's really simple to set different styles in your items and modular pages from Bootstrap Theme Patterns. That means text, buttons, labels and background colors change on each case.
I think this is usefull to "organize" in a fast view your items contextualy, and also break monotony in your site highlighting relevant content. Anyway is optional, you don't have to use this feature.
Find more help in our Styling Documentation.
Don't be afraid to fill of color your site!