  This work is part of an effort to detect secular variable objects in large
scale surveys by analysing their path in color-magnitude diagrams. To this aim,
we first present the variability morphologies in the V/V-I diagram of several
types of variable stars. They comprise both periodic and non periodic variable
stars from the Large Magellanic Cloud, such as classical Cepheids, long period
variables or Be and R Coronae Borealis stars, as well as two of the detected
secular variable stars in the Galaxy, FG Sge and V4334 Sgr. The study of the
different variability morphologies allows the identification of regions in the
color-magnitude diagram where those secular variable stars could be detected.
We also estimate the number of such secular variable stars expected in the
Large Magellanic Cloud.
