[etc]

Alex Lexcuk, учите побитовые операции.

var a:uint = 0x77;
var r:uint = 0x66;
var g:uint = 0x60;
var b:uint = 0x06;
var color:uint = ((a & 0xFF) << 24) | ((r & 0xFF) << 16) | ((g & 0xFF) << 8) | (b & 0xFF);
trace(color.toString(16));