  In this contribution I present my current work in a new generation of
evolutionary synthesis models that compute the multiwavelength energy
distribution (from gamma-rays to radio) as well as the associated dispersion
for young stellar systems. I will also show some statistical effects that may
appear in the analysis of surveys, like bimodal or multi-modal distributions
and bias when color indices computed by the codes are compared with
observations. Such new generation of synthesis models may be useful for the
analysis of the data expected from GTC.
