background-color: rgba(255, 0, 0, 0.7);
blue—along with the fourth parameter for setting opacity,
alpha—to be specified without the child elements inheriting it. In this case, the background would have been red with a 70% opacity. That’s one line of code and no images. Not a problem in AIR.
The documentation for Adobe AIR 1.5 say the CSS “opacity” property is not supported, but you can use rgba()! So nice.