BUG: Colors not rendering in IE

[manjot-cams]

This module doesn't render in IE and older browsers that do not support CSS variables. I was able to create a workaround by creating fallback CSS values for the colors that were using variables. Ideally we shouldn't have to do this.

I can post the fix I used if anyone needs it.

[matheo]

@manjot-cams please, create a GIST so we can include that in the README at least.

[f-aubert]

@manjot-cams, would you care to share?