The evolution of the colour-magnitude relation and of the star formation activity in galaxy clusters since z~0.8

We present recent results on the evolution of the colour-magnitude relation and of the star formation activity in galaxy clusters since z~0.8. Results are based on the ESO Distant Cluster Survey (EDisCS) - an ESO large programme aimed at the study of cluster structure and cluster galaxy evolution over a significant fraction of cosmic time - and are discussed in the framework of the current standard paradigm of structure formation.