Modding slopes graphics?

[bigus]

I'm not sure about Nap titles but in Civil War which should be/might be similar,
The slope outline similar to SB (hitting the contours button or view map contours) I believe is hardcoded but you can change the thickness and brightness under settings.
Then there is the 2D slopes which you can mod. In Civil War these are 2DHexSides files and are found in the Map folder.
You can turn these off and on using view.

Hope this helps.