I keep hearing that getting a decent key from a DSLR is hard on green screens, but would blue be any different, perhaps because of the color space? Is it the same and it has nothing to do with the color?
It's the 4:2:0 color space, so the color of the screen won't make a difference. That's just a matter of preference and gives you options depending on what you're shooting.
With some work you can get a decent basic key, but I wouldn't depend on these cameras for any intensive green screen work.
