Setting values for edit_sky entity through lua

So I’m making this kid a npc spawning script and he wants the sky to change to red with some fog and I’m not exactly sure how to change the sky/add fog so I thought doing something like this would accomplish it. My question is, how can I set the properties of the edit_sky through lua?

function SpookySkybox()  
	local skychanger = ents.Create("edit_sky") -- Set Colored Sky
	skychanger:SetVar( "TopColor",  ) -- Would I use something like this?

You haven’t bothered to do your own research at all, have you? Go dig around for two minutes or so. The answer already lies within the snippet you provided.