Yup! Jeremy Saulnier apparently likes naming his movies after colours.
Green Room is great, but not as great as Blue Ruin. That said, Blue Ruin's lead actor, Macon Blair, also plays a role in Green Room. Give it a shot and let us know what you think.
As for Kristy, I'm a sucker for films where evilgoers go after a young woman thinking that she'll be a seemingly easy target... and then she fights back beyond belief. I LOVE those films! So yeah, Kristy is worth a watch if you're into those, too. It's like a less-gorier version of The Strangers meets You're Next. And the soundtrack is great!
The Gallows... oh, boy. Have fun with that.
Yeah, the horror of the 70s and the 80s will always be superb, but there's some new-age gems out there, too. Most of my horror-watching has gone to the 70s and 80s, so I've been using this Halloween to catch up on more-recent horror flicks.