Coat - Should be smooth, flat, but hard, dense and abundant. The belly and underside of the thighs should not be bare.

Color - White should predominate; brindle, red or liver markings are objectionable. Otherwise this point is of little or no importance.

Amplification
The coat of the Smooth may vary in length and density according to breeding, grooming and climate, but should always be flat, with a hard topcoat. The hair under the tuck-up and inside the thighs is usually trimmed short, but not bald, as in some single coated breeds. The colors of the smooth may be solid white (as discussed earlier, eye rims should have dark pigment); white and tan; white and black, with tan shadings - all "white and black" Smooths are actually tri-colors although the amount of tan that appears over the eyes, on the cheeks, at the vent, etc., varies considerably with the individual. These tan markings are in the black are traditional and genetic and should never be colored out when grooming. Tan may be taken to mean any reasonably solid of reddish tan, with or without black points or shading. Many dogs are sable marked. Brindling should be penalized Although white should predominate, no preference of any kind should be given to placement of markings. The type, structure and character of the dog is paramount and the attractiveness or lack of it conferred by markings is extraneous to the intent of the standard. The "would-be" judge of the Smooth Fox Terrier must be ever cautions of the illusions cast by markings… many considered excellent adjudicators find themselves confusing a splash of color from the off side with a dip in the topline. Ticking on legs and body is not uncharacteristic and should on no account be penalized. Judges must also remember that the preferred coloration is more than half white over the total body mass and may be all white. The variation of markings that is possible in the breed is a part of its great heritage, to be preserved and respected by all. When evaluating the Smooth, do consider the extent to which the placement of markings affects the appearance rather than the reality of its conformation, and make every effort to assess structure rather than illusion.