  We present models predicting the magnitude, redshift, and color distributions
of field galaxies. We explore whether a fading starburst scenario can account
for the observations of faint blue galaxies. We marginally rule out a starburst
scenario with a local IMF because the models predict too many nearby faint
galaxies that are not observed. A burst model with a truncated IMF reproduces
the counts and redshift distributions well but produces too blue a population.
We show that surface brightness selection has a significant effect on the
distributions. In particular, adding a population of low-surface brightness
galaxies, known to exist locally, can explain the counts for $B_J<23$. They do
not, however, account for the steepness of the counts at fainter magnitudes.
Finally we show that the colors of galaxies in a $K$-band selected sample are
too blue to be consistent with a constant star-formation rate,
passive-evolution model.
