  We revisit the color bimodality of galaxies using the extensive EFIGI
morphological classification of nearby galaxies. The galaxy SDSS images in the
g, r and i bands are decomposed as bulge+disk using SourceXtractor++. The
spectral energy distributions made of our gri photometry complemented with
GALEX NUV are fitted with ZPEG in order to estimate the stellar masses and
specific star formations rates (sSFR) of whole galaxies as well as their bulge
and disk components. The absolute NUV-r color versus stellar mass diagram shows
a continuous relationship between the present sSFR of galaxies and their
stellar mass, that spans all morphological types of the Hubble sequence.
Irregular galaxies to Sab spirals make up the Blue Cloud, the Green Plain
(formerly Valley) is made up of early-type spirals (S0a-Sa) while the Red
Sequence contains all lenticular and elliptical galaxies, with systematically
higher masses for the ellipticals. Galaxies across the Green Plain undergo a
marked growth by a factor 2 to 3 in their bulge-to-total mass ratio and a
systematic profile change from pseudo to classical bulges, as well as a
significant reddening interpreted as star formation fading in their disks.
Therefore, the Green Plain is a transition region, and we exclude a
predominantly quick transit due to rapid quenching. We suggest that tracers of
increased star formation (bright HII regions, spiral arms, flocculence)
determine the limited scatter of the Main Sequence of star-forming galaxies.
The high frequency of bars for all spirals as well as the stronger spiral arms
and flocculence in the knee of the Green Plain suggest that internal dynamics,
likely triggered by flybys or mergers, may be the key to the bulge growth of
massive disk galaxies, marker of the aging of galaxies from star forming to
quiescence. The Hubble sequence can then be considered as an inverse sequence
of galaxy physical evolution.
