The dynamic noninvasive imaging of colloidal nanostructures has been precluded by the diffraction-limited resolution of (confocal) light microscopy Using Fast Stimulated Emission Depletion (STED) microscopy, we demonstrate the ability to resolve the formation of a colloidal crystal (monolayer) from particles of 200 nm size, where the voids in the crystal are as small as 30 nm With a temporal resolution or 5 ms, we exemplify the technique by visualizing the annealing of potential point detects (luring the formation of the colloidal crystal