It's a color problem, but also a attention problem. Playing Stardward Rogue takes up a lot of mental resources. When streamers play they don't have enough mental capacity to play well and talk, so they end up doing both to varying degrees of success. You'll notice that he frequently just ran into a room without any hesitating at the doors. He catches a lot of stray shots and caltrops this way. Also, when playing he walks over them, and then does it several times in a row.
Perhaps having tileset specific caltrops that stand out more?
