Great thread.
Here's my run of Chuck Klein's. The only color I know I'm missing is a green/blue tint. I haven't seen any other color tints other than those I own + the green/blue variation. I have always assumed there is a yellow out there, but I don't recall seeing one. Please let me know if you have or have seen any color I don't already have below. I'd be scared to learn that I also need an Orange, a Pink, and the three "Dual Color" variations that Scott listed.
I have my Klein run listed as: (1) Black & White, (2) Blue, (3) Green, (4) Sepia, (5) Light Green, (6) Purple, (7) Red, and (8) Brown. I think my scanner was "funky" with the red one as it is a little more red than shown.
It's pretty clear that my two green ones are very different shades of green. Also, there is a pretty clear distinction between the brown and sepia versions. I'm not sure if this throws a wrench in Scott's original post at all.
Here's the Green/Blue tint that I don't own:
Would love to see any other color variations of Mr. Klein.