1. Kicking off the collection is Wallace Erickâs custom select menu styles. They behave slightly differently than standard HTML selects, and I think theyâre a little nicer to use. Here's the CSS that I've added to formdesigner.css.z_co_dropdown { width: 120px ⦠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 ? Examples and source code download included. The option to activate the state, corresponding to the eventkey in the Dropdown.item. No JavaScript needed. Does anyone know how I can adjust the options as well? But unfortunately, it cannot easily style with CSS to customize. SOLUTION 1: