In my garage, I had to replace a bunch of drywall due to flooding. So I
had it replaced and needed to repaint it. Unfortunately, I have no clue
as to the exact paint color used in the garage by the prior owners. I
went to HD and had them color match it and they got very close. The
paint color is white but slightly yellowish white in case anyone was
wondering.

The mixed paint turned out not to be exact. While it doesn't stand out
too badly, it is also is visibly different if you look directly at it
in good light. The new paint is slightly too white and not as yellowish
as it needs to be. It doesn't stand out too much but its certainly not
a perfect match.

So I was wondering if this is probably as good as it gets and I should
just quit while I'm ahead or if it might be possible to get an exact
match with further attempts. Would it be possible to get an exact match
or will almost but not perfectly matching paint is what I can ever
expect no matter how many times I try to mix an exact match to the old
paint?

What is people's experience on this?