Angular ui-select multi select：从控制器中选择一些项目时，Dropdown没有更新

On click of "select yellow color" button, I want to add yellow to the selected list. Yellow is getting selected, but the dropdown is still showing yellow. In the same way, I want to deselect yellow on click of "deselect yellow color" button. I am able to deselect yellow, but yellow is not appearing in the dropdown. Please help me with this issue. HTML:On click of "select yellow color" button, I wan