You can't get a good color match until the wood is sealed and finished, and woods with a natural finish usually get darker as they age. A burn-in putty stick is your best bet to hide the small seam. Sometimes I use tinted 5 minute epoxy but you have to be careful not to make a mess. Universal tinting colors (UTC) are available in tubes almost everywhere. First put masking tape on each side of the seam close to the joint, then use a putty knife to squeegee off the excess epoxy. Let dry over night and carefully sand level. Glue shrinks as it dries so it is not a good choice, epoxy does not shrink.
Experiment on scraps first, repair the cabinets only when you get your technique perfected.
Wayne