Script for creating your own theme decals.

ThemeDecals_Script.cs

// You MUST use a unique diffuse texture (put whatever texture in it) to avoid unforeseen consequences!

// Import a decal or a big decal as usual and run this script using the texture tag you want:
//themedecal-grass
//themedecal-cliff
//themedecal-sand
//themedecal-gravel
//themedecal-ruined
//themedecal-oil
//themedecal-ore 
//themedecal-pavement

var asset = ToolsModifierControl.toolController.m_editPrefabInfo as PropInfo;
asset.m_mesh.name="themedecal-grass"; //CHANGE THE TAG HERE