You spent hours choosing the perfect paint color and covered every wall with care. But years later, a touch-up is needed—and you can’t remember if the shade of green was Phantom Mist or Dinner Mint.

If cabinets are part of your touch-up project, unscrew a cabinet door. Take the entire door to the paint store to be color matched. Reattach the door to the cabinet when done. If drawers are part of ...