Bootstrap 3单击后折叠导航栏颜色

Question

我希望在点击后更改折叠导航栏的默认颜色样式。我在折叠之前成功地设计了样式，但之后无法找到如何改变颜色。

W3Schools的例子：

function getHistory() {
    HistoryFactory.getHistory(vm.includeCancelled).then(
        function(response) {
            _.each(response.data, function(upload) {
                upload.inProgress = upload.status && ['INPROGRESS','NEW'].indexOf(upload.status.statusCd.trim()) > -1;
            });
            vm.uploads = response.data;

            if($state.params.reupload){
                uploadProductionData();
                $state.params.reupload = false;
            }

            // Now call setPage after data is finished
            vm.setPage(1);
        });
}