This lecture presents an improved algorithm for solving three-color parity games, introducing the concept of progress measures and their acceleration. It covers the main properties of parity games, the complexity of computing winning states, and the progress measure algorithm with update rules. The gap theorem and time divergence in reachability games are discussed, along with the symbolic implementation of accelerated progress measures. Experimental results and conclusions on the practical speed-up provided by acceleration are highlighted, with future work focusing on extending the algorithm to general parity games.