var magentaRed:int = 255;
var magentaGreen:int = 0;
var magentaBlue:int = 255;
var magentaHex:uint = RGBToHex(magentaRed, magentaGreen, magentaBlue);
trace("magentaHex: ", magentaHex);

function RGBToHex(r:int, g:int, b:int):uint
{
	var hex:uint = r << 16 | g << 8 | b;
	return hex;
}

// OUTPUT
// 16711935

AS3 RGB Colour to Hex Colour (uint)

color, convert

ActionScript 3