Sounds odd - I'm not sure why that would be. It could be that in the platform in which it's black, it's simply not supported. I'd try making a lerp node, lerp between red and green, and then plug in a UV coordinate V output into the T input of the lerp node, and see how it looks on the two devices

This is now been fixed in 1.20

As of 1.20, you can now rotate the lights using RMB :)

This has been possible since SF 1.10

This is now easily done using the Smoothstep node as of 1.20

This has now been added in 1.20

Closed due to age

That's not very good :(
Unfortunately I can't look into this until I have time for it, which is in a few days

I can probably fix that for the next version :)

Glad it was resolved!