  We construct evolutionary synthesis models for simple stellar populations
using the evolutionary tracks from the Padova group (1993, 1994), theoretical
colour calibrations from Lejeune et al., and fit functions for stellar
atmospheric indices from Worthey et al..
  A Monte-Carlo technique allows us to obtain a smooth time evolution of both
broad band colours in UBVRIK and a series of stellar absorption features for
Single Burst Stellar Populations ({\bf SSPs}). We present colours and indices
for SSPs with ages from $1 \cdot 10^9$ yrs to $1.6 \cdot 10^{10}$ yrs and
metallicities $[M/H]$ = -2.3, -1.7, -0.7, -0.4, 0.0 and 0.4.
  Model colours and indices at an age of about a Hubble time are in good
agreement with observed colours and indices of the Galactic and M 31 GCs.
