  In this paper, we analyze period color and amplitude color relations at
minimum, mean and maximum $V$ band light for 6391 RRab stars in the Large
Magellanic Cloud obtained by the MACHO project. Specifically, we find that
color and amplitude are nearly independent of period at minimum light but that
there exists a definite relation between period and color and amplitude and
color at maximum light. These two properties are easily explained by the
application of the Stefan Boltzmann law and the interaction of the photosphere
and hydrogen ionization front at minimum light. When we examine the slope of
the period color relation as a function of phase, we find that the slope varies
significantly with phase and is small for a wide range of phases around minimum
light. This suggests that another factor that needs to be considered when
trying to understand RR Lyrae observed properties is their behavior at
different phases during a pulsation cycle.
