How do I repair a small chip in a laminate floor?
That looks like the chip is in the transition piece and not the floor boards.  For the best results, just replace the entire piece. It doesn't look like it matches exactly anyways, so just try to find something very close.  If you know where the floors came from you might get really lucky and end up with the identical part.

It is either glued in place, friction fitted to a track or nailed (this can't determined from the pic).  Either way, you need to carefuly pry it up, being careful not to damage the floor.  Install the new one as-instructed or buy some construction adhesive and glue it back down and put a few phone books on it until it dries.  Make sure to wipe up any excess glue with a damp rag before it dries.  It was likely cut to fit so you will need to cut the new piece.  If you don't have a saw to do this, take a measurement (measure twice, cut once!) with to where you are buying it and see if they will cut it for you.

The other methods you mentioned are suitable alternatives. If the color is matched well, it won't be very noticeable when standing. Crawling, maybe.