The Skybox add-on will help you make beautiful scenes in Unity 3d. It contains 10 different skyboxes which you can use to give your scenes a more lively feel.
The package contains:
-5 night skyboxes with different colors
-3 Day skyboxes
-2 dawn skyboxes
You can also edit the skyboxes in Photoshop or any other image editor. We included a Read Me that shows you to do it. And if you aren't satisfied with the existing ones we also show you how to create your own skyboxes in that read me.