With a razor knife, or blade, cut a small patch of paint and bring it to any paint store. They will match it dead on. Unfortunately some areas will have changed because of light. Kitchens also have grease even if you can't see it.
The only issue will be the sheen as paint changes in time.
What I would do is paint those areas and the wall up to the corner. Anywhere you stop will be visible. If you go to the corner, not so much.