To elaborate, if you did this...
...it would trace 34. That's super - I know it was a 32 bit value that was defined. But if you compared these two values...
var color:uint = 0x22FFFFFF;
var theAlpha:uint = color >> 24 & 0xFF;
Both will come back as 0. The 32 bit value had the alpha defined as 0, whereas the 24 bit value didn't specify, so the bits extracted are empty (which is 0).
var color32:uint = 0x00FFFFFF;
var color24:uint = 0xFFFFFF;
var alpha32:uint = color32 >> 24 & 0xFF;
var alpha24:uint = color24 >> 24 & 0xFF;
trace(alpha32 + ", " + alpha24);
So this method is great for all color values except when you specify 0 alpha in the color. At that point you can't discern between a 32 bit value and a 24 bit one. So, does anyone know of another method I might use?