Look for wood putty that matches the color of the wood floor. Wood putty is available in several colors but it may be difficult to find one that matches the wood exactly. If that is the case, purchase two or more colors that are as close as possible to the color of the floor.
Take a small amount of both putty colors and mix them together with your hands. Add putty as needed until you achieve the desired color.
Place the colored putty on the end of your finger or the end of a flat-head screwdriver. Choose a tack hole in a hidden corner and place the mixed putty on top of the tack hole, pushing a little down into the hole.
Use a putty knife or piece of straight cardboard to skim off the excess so that the wood putty is flush with the floor.
Examine the floor to check the color. Remix the putty if necessary, apply it to the tack hole again and check for color accuracy.
Allow the putty and allow it to dry for the time suggested by the manufacturer.