Noticed and was wondering about that object myself. Structurally it appears that it could be two galaxies in collision. But why does it appear so blue? It appears too small to be a foreground object the size of galaxies. If at the distance of the galaxy cluster and appearing that color, it would be in the ultraviolet portion of the spectrum if it were nearby. Curious object.
Another thought: if it is two galaxies in collision, there may be a a burst of star formation activity taking place. Young, massive stars are extremely hot, emitting blue and violet light.