You have to mix that color. There's nothing really available that approximates it; believe me, I know! I think I added red and purple to tan and brown, and just swirl it around on a palette until you get a close match. Don't use too much purple or red, and don't bother trying to mix up a bottle of it, you'll never use it all! Mix the greens too--for the blackish green borders you can use Tamiya Black Green, but the light green you can easily come close with white added to a standard green.
The key is to experiment! That's how you'll learn! I used to be the same way--freaking out about "exact color matches" until I just started experimenting out of frustration. Now, there's not a color in the world that intimidates me! Practice and learn!