Physicists Bart van Dam and Katerina Newell (Dohnalova) from the UvA Institute of Physics, in collaboration with Emanuele Marino and Peter Schall as well as colleagues from the University of Twente and Jiljin University in China, have shown that a single nanoparticle can be used to emit different colours of light. Their results, which were published in the nano- and microphysics journal Small, show that the particles under consideration may be a very efficient and versatile tool to produce light of all colours at tiny scales.