I’m new to blender and am trying to find out why my “Cycles render” rendered output is looking red, rather than how it does in the live preview. It looks like this: http://cl.ly/2K1a2t0G3R0G0M0J061r
My blender is below.
stairs2.blend (436 KB)
Hi nonlinearmind, I’ve checked out your blend.
1st up there’s a few things to fix to make your blend render a lot quicker in cycles and other things to improve the geometry.
Try not to use a subsurf modifier with more than 3 for the render, its overkill - I think you had it at 6 on the central pillar. The cyclinders needs to have edge loops at the ends (“CTRL+R”) to stop them tapering with the subsurf and creating an ugly mesh as in this screenshot…
This is also a problem on the posts on the stairs.
The light emitting plane is very small and would be better if it was at least 4 times the size.
A scene like this rendered on my GPU should take no less than a few seconds to build the BVH, it takes nearly a minute at the moment - even the preview is very slow.
As you’re using a glass shader for the central pillar, there’s nothing really to reflect. Maybe make a curved “L” shaped studio plane for the floor and background. Maybe another emitter from another angle and perhaps with a different colour would be good too.
Make these changes first and see how you get on, and maybe the odd colour will dissapear.
Post back if you have anymore questions/problems 
If you’ve modified you file for the improved geometry as I suggested, paste up a link and I’ll have another look to see what may be going on 
It’s probably something simple, in the mean-time have you tried re-installing blender, in case you’ve changed a default you’re unaware of?
