Choose a population size of 10 and the determine the average number of generations necessary to see an allele fix (so that all members of the population are the same color).
If you don't get fixation in 20 generations, repeat the simulation but with 30 generations. For each simulation, record the time to fixation.
Follow this procedure until you have data for 5 trials where the allele became fixed. Then calculate the mean time to fixation.