  Some fine structures can nowadays be identified in the high-quality
colour-magnitude diagrams (CMD) of Local Group galaxies. The clump of red
giants, for instance, may present a significant colour spread, and extensions
to both brighter and fainter luminosities. Such features are predicted by
population synthesis models which consider stars in the complete relevant
ranges of ages and metallicities, and are potentially useful for constraining
the star formation histories of the parent galaxies over scales of gigayears.
We briefly comment the cases of fields in the Magellanic Clouds, M31, and the
local CMD from Hipparcos.
