Problem for me is that all these colours end up looking muted and washed out. It's not that they don't have them, they were clearly there when they shot, but then a lot of their films just make them look washed out. Iron Man in Civil War always stuck out to me in that regard, especially looking at the first Iron Man. Wonder Woman's third act definitely had issues, but that movie looked good. It also used the colour palette to tell it's story, with the obvious different look between Themyscira and WWI, but also the blue WWI backdrop around her costume, but not applying that look to the costume giving it a chance to really pop when it came out on the battlefield. SS and BVS? No argument here. BVS has some moments, but Suicide Squad is awful in it's own way. As for Logan, there is not one film in the MCU I'd say looked as good as that. I'd go as far as to say it's right with the Nolan trilogy as far as best looking superhero films go. Bland's the last word I'd use for this:
It's not because it's 'edgy', it's because I think the colour grading looks much better and because they know where to point the camera to create interesting and memorable imagery. My go to example would be the X at the end. It's also not because the MCU is 'normal', whatever that means, it's because I find their standard colour grading that they've adopted for most of their movies since the start of phase 2 looks bland and takes something away from what's on screen for me. Guardians 2, I appreciated that the colours didn't have that ugly muted look I have a problem with, and I really do hope that's an indication of that problem dropping by the way side in the future, rather than them making an exception.
But that's just me and all that.