Example to custom css background

[Roger Correa]

Please,

I need find one example to custom CSS background-color in the message.
In the code below assertive-bg class it's configured but not changed nothing.
My code is here:
`.factory('msg', function ($timeout, blockUI) {

        return {
            display: function (msg, type) {

                if (type !== null){
                    blockUIConfig.cssClass = 'assertive-bg';
                } else{
                    blockUIConfig.cssClass = 'block-ui block-ui-anim-fade';
                }

                blockUI.start({
                    message: msg
                });

                $timeout(function () {
                    blockUI.stop();
                }, 2000);
            }
        }
    })`

[Juan Ignacio Alvarez]

Hi
I need delete the massege, and set a circular progress. You know if that is possible?