Kendo MVVM异步背景颜色绑定

I am trying to do something very simple and straight forward. I want to click a (class="AccentSquares") that I have made into colored squares. Each square's color corresponds to a different theme color. The bar at the top(class="MobileNewAccountHeader"), which is defaulted to "purple", should change to the color of the square that I am clicking. Here is what I have.I am trying to do something very simple and str