Having looked at the Blu-Rays of unaltered TOS, the following episodes need some color-correction:
1x23 The Return of the Archons
2x25 The Omega Glory
2x26 Assignment: Earth
3x05 And the Children Shall Lead
3x12 Plato’s Stepchildren
3x13 Wink of an Eye
3x19 The Cloud Minders
3x21 Requiem for Methuselah
3x22 The Savage Curtain
3x23 All Our Yesterdays
These episodes have a yellowish tint on the Blu-Rays.
Another thing that could be corrected is the opening title and credits after the teaser (the “Space: the final frontier” bit) of the 2nd and 3rd season episodes. The red-green-blue is misaligned on them.
All episodes are zoomed in a little on the Blu-Rays (outer margins trimmed off). DNR is apparent when comparing the standard episode of the 2nd pilot (“Where No Man Has Gone Before”) against the unaired pilot version which is included unrestored from film. Near the end when Gary is zapping people, the zaps are partially removed by DNR on the standard episode. The zoom framing can be seen by comparing these two titles, too.