Recent self-assembly of ultra-bright fluorescent colloidal mesoporous (nanoporous) silica particles is highlighted. The particles can be up to two others of magnitude brighter than polymeric particles of comparable size assembled with quantum dots. Comparing with the maximum fluorescence of free dye in the same volume, the particles can show fluorescence which is higher by more than three orders of magnitude. We discuss the nature of the high brightness of these particles, existing problems, potential applications and prospects.