Despite the (still disputed) result of Appel and Haken [1] on the 4-colorability of planar graphs, optimal coloring of planar graphs is still a hard computational problem for which the study and comparison of exact and approximate algorithms is of great relevance. This paper presents experimental results on the coloration of graphs by means of ten different methods, two of which are exact methods (one by backtracking and one based on a modification of an algorithm suggested by Randall-Brown). Beside showing the (obviously expected) bad running time of exact methods, the paper sheds some light on the behavior of approximate algorithms. The experiments are run on sets of 200 graphs generated by three different randomized procedures. The most meaningful results concern graphs of 50 up to 200 vertices and show the superiority of the extended reduction algorithm. Unfortunately, algorithms are simply sketched and the reader should look at the original papers in order to fully understand the most interesting improvements.