  We present a technique for decomposing Cepheid light curves into their
fundamental constituent parts; that is, their radius and temperature
variations. We demonstrate that any given pair of optical luminosity and color
curves can be used to predict the shape, amplitude and phase of a Cepheid's
light variation at any other wavelength. With such predictions in hand, a
single new observation at any given new wavelength can be used to normalize the
properties of the predicted light curve, and in specific, derive a precise
value of the time-averaged mean. We suggest that this method will be of great
advantage in efficiently observing and precisely obtaining the mean properties
of known Cepheids scheduled to be observed at new wavelengths, specifically in
the mid-infrared where JWST will be operating.
