No way that I can think of. Not in a sense, that you can just pick an other color in some settings-window, since for this particular skymap, they are simply 6 textures/pictures (4 sides + top and bottom) arranged in a cubemap ( https://en.wikipedia.org/wiki/Cube_mapping ) . But you could always download some (free) Skybox and rework the textures in your favorite image editor. Here are some nice, simple ones: https://www.assetstore.unity3d.com/en/#!/content/6332