First of all, thanks for developping and sharing your software for free!
I've just started using Natron today, and am so far rather impressed. I'm working on a project where I render a watch in 3d, and am rebuilding the beauty, and making colour variations in Natron. I work with float 16 exrs.
I want to multiply my current (white) dial by a colour, and mask it with the red channel of my mask.
When I do so, I get visible edging.
Fiddling with the "output colour space" gives me various results, some of them better than other, but overall, it doesn't feel like I'm doing the right thing. Any advice?