The default shaders in Orcs Must Die! Unleashed are not optimized for older systems. This may cause trap and player models to appear black.
Following these steps can help ensure all of your orcs are smashed in vibrant color:
1. Select the gear icon on the dashboard. This will take you to the Game Menu.
2. Click on Run Performance Test.
3. Once the performance test has loaded and you're able to move freely, hit the Escape key on your keyboard to bring up the Pause Menu.
4. Click on the Options button, and then select "Video".
5. Scroll to the bottom of the list and click on the Advanced Settings button.
6. Toggle the Dynamic Lighting field down to the Medium setting.
7. Click on Close and then Accept.
Your models and traps should now display properly. If you continue to experience issues, follow these steps again and the Dynamic Lighting field to Low instead of Medium.
If this solution does not fix the problem, please gather screenshots of your Advanced Settings menu, your DxDiag, and your log files and send them our way. More information on your log files and where to find them can be found here.