First of all get all the files you will be needing. For a guide on where to find the correct files, especially the specular files, go to this thread and download the attachment:
For this guide I will be using the Famas as an example. So get your files ready.
After converting them to DDS, and properly organizing your originals and mods, lets open it up and start. Here is the unmodified specular file for the Famas:
For this tutorial, we will be using one color for the entire thing. The color can change slightly, But its reccomended that you stick with just this one. The color is #ffba52
Select the areas that you want to have gold:
With your brush settings as so, cover the entire area with our color:
This is where it can get interesting. The alpha channel. First off, to get a dull shine, you will need to select a gray color. For the first screenshot I used a slightly lighter gray, but this one is fairly darker, and you will see the difference it makes:
Alternitivley, you can simply turn the slected area white, and end up with a very reflective surface, that is much closer to that of CoD4's golden style.
Here is the in game effects:
Dark gray alpha:
Lighter Gray alpha:
Playing around with these effects will give you different variations on you gold's reflectivity, and tint. Also feel free to mess with the color itself, but for the best effect, keep it close to what I use.
No make sure to save your work, fix it, and go in game to check it out. Always remember to turn specular mapping on, to be able to see this. Another reason why I like this, is because when you turn specular mapping off, you will have just the regular colored gun, while the other methods will give a nasty look
Now remember: This is only one of the methods, and the simplest. Adjusting the colors and alpha channels using this tutorial will give many different results, but other methods are capable of producing cleaner, crisper, or brighter camos. However, by using this tutorial you should be able to grasp the basics of how gold will work. Feel free to modify the techniques for different guns, to get different effects.
An example of altering this tutorial, would be to set the brush settings to color dodge on the specular file, and using the Hue/Saturation filter to turn the color file to a goldish color, to achieve a bright crisp gold like so:
Also, certain methods may not work or have the same effects on all guns. Each gun will require a certain technique, and most likely adjustments to each of those techniques.
I realize this tut might not be incredibly noob friendly, but like I said, it helps if you have a good grasp on what you are doing when it comes to modding before hand. If anybody has ANY questions on gold, or wants to request a golden gun, feel free to ask here. And just one more time: This is just ONE of the ways to do gold, but its the simplest. This tut was aimed to show a simple way, but there are more complicated, and better ways out there.