Blue background?

[Malfunction]

I see in people's screenshots that they have blue backgrounds in hammer in the 3d view. I just started mapping, and I think I'd prefer that over straight black. How do I do this?

 

[^PoW^norman b.]

Do you mean like a sky? If you do, you need to close any gaps in your map with brushes that have the tools/skybox texture or something like that. The "gaps" i'm referring to are any places that exit out in to the black void in the hammer editor.

 

[StardogChampion]

If the 3D view was blue, then obviously they were looking at a blue part of their map

If you want to change the other views, as far as I know the only other colour you can make them is white.