Create responsive images on the fly with php and Imagick

To improve paging loading performance across multiple devices, web developers can provide each image in different resolutions using the srcset attribute and let the browser choose which one to load e.g.:

CSS trick: Setting background color of a selected HTML option element

Update 02.02.2018: As noted by Tom this now only works when the attribute multiple is set. Have you ever wanted to set the background color of a selected OPTION element of a drop down ? Unfortunately, setting the CSS background-color property does not work for (most/all?) browsers, but there is a workaround using the background-image …