  We investigate the properties of bright galaxies with various morphological
types in Abell 1139 and Abell 2589, using the pixel color-magnitude diagram
(pCMD) analysis technique. The sample is 32 galaxies brighter than Mr = -21.3
mag with spectroscopic redshifts, which are deeply imaged in the g and r bands
using the MegaCam mounted on the Canada-France-Hawaii Telescope. After masking
contaminants with two-step procedures, we examine how the detailed properties
in pCMDs depend on galaxy morphology and infrared color. The mean g - r color
as a function of surface brightness (mu_r) in the pCMD of a galaxy shows fine
performance in distinguishing between early- and late-type galaxies, but it is
not perfect because of the similarity between elliptical galaxies and
bulge-dominated spiral galaxies. On the other hand, the g - r color dispersion
as a function of mu_r works better. We find that the best set of parameters for
galaxy classification is the combination of the minimum color dispersion at
mu_r <= 21.2 mag/arcsec^2 and the maximum color dispersion at 20.0 <= mu_r <=
21.0 mag/arcsec^2: the latter reflects the complexity of stellar populations at
the disk component in a typical spiral galaxy. Finally, the color dispersion
measurements of an elliptical galaxy appear to be correlated with the WISE
infrared color ([4.6] - [12]). This indicates that the complexity of stellar
populations in an elliptical galaxy is related with its recent star formation
activities. From this observational evidence, we infer that gas-rich minor
mergers or gas interactions may have usually happened during the recent growth
of massive elliptical galaxies.
