Thanks, everyone!
My camera is not the best at taking true-to-life photos. This one was optimized for color saturation (not value), and so I think some of them might be a bit off. A lot of the darker colors in the scale look different than the photo, but you're right about #3 and #4. I switched them, and then I took a new photo of them in black and white (not changing to black and white on the computer), and it seems to be a better representation.
As for the second to last fabric, I've had misgivings about it, too. The leaves are much less brown in real life, more of an algae green, and the white background is actually a warm ecru. You can't see in the photo, but it has birds and much more densely-patterned areas. I love it, but I can understand the problems. Guess I'll look through my stash.
I'll think about something to replace that middle fabric, though. I wanted to stay away from making of quilt of basically tonals. I wanted some variation and texture, which means that the print doesn't necessarily need to be constant throughout - in the scheme of the whole quilt, it should still accomplish the grading. But it is a big change, not just a small one, so I'll look around. I've been to the fabric store about 4 times and I've pretty much exhausted their selection, so these represent the best set I could muster :/ If there's a solution, it'll have to be in my stash.
I also have to be conscious of color. I'm not making a single-color bargello, and so I can't move things around based soley on value. For instance, moving #8 to a higher number looks alright in black and white, but it sticks out like a sore thumb in color because it's much more green than the light blues that would be around it.