Render help

[bobthe2lol]

So I want to render a sphere. I tried just doing render.DrawSphere, but I realized I needed a texture too. I would preferably like a semi-opaque solid red sphere. Anyone know how I can go about this? Here's my code:

debugmat = Material("models/debug/debugwhite", "")

function GM:PostDrawOpaqueRenderables()
	if selectStart then
		center = (LocalPlayer():GetEyeTrace().HitPos+selectStart)/2
		render.SetMaterial(debugmat)
		render.DrawSphere(center,(LocalPlayer():GetEyeTrace().HitPos-selectStart):Length()/2,20,20,Color(255,0,0,100))
	end
end

This just draws a solid, opaque black sphere. Even though the color is red...

[Ilyaaa]

[lua]render.SetBlend( .1 )
and
render.SetColorModulation( 1, 0, 0)[/lua]

May or may not help.