Huang et al. (1994) have conducted an extensive photometric campaign on the prototypical nonradially pulsating (NRP) star 53 Per and confirmed the pair of frequencies at 0.46 cy d-1 (dominant) and 0.60 cy d-1 originally reported by BS79. In an analysis of these two modes, SP79 underestimated the effects of the Balmer jump on this star's color variation, leading them to an erroneous conclusion that geometric effects dominate the color variations and also that the modes are described by indices l=3, -m = 3 and 2. Herein we describe results from Voyager 2 observations obtained during Lin's optical campaign. The amplitudes derived for these Far-UV data using the optical ephemeris provide for the first time a large enough wavelength baseline to discriminate in favor of thermal effects over geometrical ones in producing NRP light variations. In addition, they allow the dominant mode to be constrained to l = 2 (or 1).