We investigate the broadband optical emission of diffuse intergalactic stars in galaxy clusters at $z\sim0.25$ by means of an image stacking technique. The images of 654 clusters, selected with the max-BCG algorithm from a subsample of the SDSS-Data Release 1 (DR1), have been stacked after masking all the sources detected down to very low S/N. The resulting images in the g, r and i bands provide reliable photometric data at the level of $\gtrsim30$ mag$/\square$” (r band), out to $\gtrsim 600$ kpc from the Brightest Cluster Galaxy (BCG). Our analysis shows that: i) the IntraCluster Light (ICL) is much more concentrated than the galaxy light, contributing $\sim$30% of the total cluster optical emission at $R=100$ kpc, but less than 10% at $R > 500$ kpc; ii) the ICL contributes between 15 and 20% of the total cluster optical luminosity between the optical radius ($\mu_r=25$ mag$/\square$”) of the BCG and 500 kpc; iii) the colours of the ICL are consistent with the global colours of the cluster galaxies, with little evidence for redder g$-$r.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html