Change the background color of the select list - Forums - Crosstec
Multi Select metadata field - Box Developer Documentation
css - How to change the border color of the dropdown box of select? - Stack Overflow
javascript - Jquery change() dont work on select box when contain only one item - Stack Overflow
change Icon color and background color based on select box using jquery
GitHub - PhilippeMarcMeyer/vanillaSelectBox: A dropdown menu with lots of features that takes a select tag and transforms it into a single or multi- select menu with 1 or 2 levels