Here is my collection of Toned Lincoln Proofs that I have recently imaged with some guidance from some friends.
Looking pretty good. Color looks great. I think the main problem you are experiencing with these are with focus. Manual focus is the best way to go if possible. Auto focus sometimes zeroes in on the wrong area.
Wow! Those colors are all over the place! Beautiful collection; my favorite is that 1959 with those neon pink and green hues.