public static int rgbToHex(int r, int g, int b)
{
    return r << 16 ^ g << 8 ^ b;
}

public static String rgbToHexReturnStr(int r, int g, int b)
{
    int nHex = r << 16 ^ g << 8 ^ b;
    return "0x" + Integer.toHexString(nHex);
}