do you have your hex code in the quotes
"#ff0000";
also this code must match the element’s style background color.
One thing to note, I believe Hype uses rgb for it’s backgroundColor attribute so instead of Hex you could use rgb(num, num, num) (“num” representing a value from 0 - 255)
http://hex.colorrrs.com/ (converter from hex to rgb)
So, red would be rgb(255, 0, 0)