There is a way to change the color of parts that are not mapped to texture sheets such as you have here.
You will need a utility from Martin Wright, author of DXTBmp.
Here is a link to his website -
http://www.mnwright.btinternet.co.uk/Once there, on the left side click on "Beta Programs".
Scroll down till you find MDLMat and click on the yellow dot to DL.
This program scans the .mdl file and displays in a graphic interface what it finds. There you can change the colors to what you like.
A couple notes.
Back up the .mdl file before you start this in case you royally mess things up. I also copy the .mdl file to the desktop as MDLMat looks there first when you open a file and this way you don't have to repeatedly navigate to the FS folder.
The interface does not display the actual model, what you get is a table listing offset and RGB values.
This is a hit or miss process due to the fact you have no control over what parts of the plane are any given material, just the color of that material.
So you may end up with undesirable results, recoloring parts of a plane you don't want.
Also, since you are modifying the .mdl file as opposed to a texture your changes will show up on all liveries that use that .mdl file. You can work around this by using multiple model folders.
Finally, I am not advocating use of this process for redistribution without consent of the original developer, but for your own use only. Distributing modifications to the .mdl file could be considered violation of an EULA by some.
Hope this helps,
Joe
Don't argue with idiots, they drag you down to their level and beat you with experience.