We needed to display list of holidays in a small web widget & Mobile list view as shown in the below screenshots which we created as html, css calendar icons in different colors for each day in a week. We could have used images but it demands multiple images or we could have used font-awesome/glyph icons but it has limited support for colours [gradient effects etc.]. HTML/CSS3 is simple and elegant.
You can see the sample html & css code live in my jsFiddle. Alternatively the html & css snippets is kept in my Gist