If you tried to add an image to your post, that did not appear in your thread.
The case you tried to repair was on the computer at the time? Or, had you
removed the case and attempted the repair whilst it was off the computer?
Since superglue can cause heat when it cures, and also affects most all
kinds of plastic (or even metal, due to its out-gassing while it cures) a
discoloration can happen and it may also be imbedded into the surface.
If the computer itself now has a visual defect from superglue on the
protective case (if it was on the MacBook while you glued it) then
the matter of further removing evidence may be involved. A visit to an
Apple Store genius, an appointment or call ahead to ask if one there
can help; or a visit to an authorized Apple service provider, who may
have some cleaning product, or an ideas... Could be if the computer's
case now has some problem due to close proximity to curing glue fumes
or heat, the damage may be somewhat permanent.
[So you were not very clear on what exactly was affected, in the absence
of image or visual evidence on this factor, at this end of the discussion.]
The computer's case likely had a protective coating on it, so if superglue
was on an external case and it or heat from it, affected the actual Mac,
then it may be difficult to restore an original MacBook finish, to like-new.
Although there are cleaning products suggested to clean these computers,
none of them were likely to be of industrial strength or restorative capacity.
Good luck & happy computing! 🙂