Changes to using core-style

I made some changes to the web-loader to take advantage of the `core-style` type element instead of the inline databound style tags. The inline style tags were causing an issue with the ShadowDom polyfill in IE. Modifying the color of the elements this way doesn't cause a problem and also has the added benefit of allowing the user to override anything else they may want within the element style-wise without modifying the core element.