The Skybox properties available for customization include:
Skybox. Checkbox that indicates whether the Skybox is turned on or off. The background will display a blank white color if turned off.
Background Color. The primary color of the Skybox. Click on the colored box to open a color picker.
Background Color Bottom. The secondary color of the Skybox. Click on the colored box to open a color picker.
Custom Skybox Type. This contains a list of possible gradient types. By default the Skybox is set to RectagularGrid, but options include SphericalSmoothGrid, SphericalFlatGrid, and SphericalInvertedFlatGrid.
Two more properties are available for editing via Expert mode:
Skybox Corner Strength. Depending on the Type/style of skybox chosen in Custom Skybox type, this can be modified to increase/decrease the intensity of the corners’ light. Any positive decimal value can be entered here (if set to 0 or lower, it will display black).
SkyBox Resolution. Dictates the intensity of the gradient in the background. A lower value is a softer gradient, a higher value is a sharper gradient. By default, it is set to 512.
Preset skyboxes are available in Editor which can meet most circumstances when its necessary to introduce a skybox to the scene.
To choose a preset skybox we need to step into Setup node by double clicking it.
After stepping into Setup node, select the Main Camera and make sure the Properties tab is active.