There is something wrong with the color profile and dynamic range in this build.
Contrast is crushing any subtle darkness to absolute black, overexposing brightness, and even color is off. I'm in video production and I watch my edited work back almost daily through the Roku Media Player on my Sharp-brand Roku TV so it jumped out at me immediately. I spent a few minutes flipping through the TV's settings wondering if I'd somehow accidentally changed something, but no... It's the app and it's the 1541 build. All other Roku 'channels' are fine.
I would guess a 709 color profile with possibly a change in dynamic range (partial/full) are collectively causing this? Just a shot in the dark there. But whatever it is, the luma values are being crushed to literally unwatchable levels in dark scenes. I'll add that I use a pure red color card at the open of all my edits that appears orange-tinted and slightly muted after today's patch. But with the luma values like this, it's hard to talk color more than to say: it isn't right!
These are H264 .mp4's rendered through Adobe Media Encoder 2017 at 1080p, 60fps, variable bit rate, 20Mbps max/target.
Until this patch, my exports have always come through Media Player with the same contrast and color as my reference monitor. (I'm not imagining it.)
If you need to wait and see if others report the issue before addressing it, is there any way for me to rollback to the last build so I can keep using the app? It's important to me that I be able to review my edits on a consumer television.
P.S: The app definitely seems quicker to respond in the latest build. So good work, there.