Photoluminescence (PL) is light emission from a substance after the absorption of photons stimulated by temperature, electricity, pressure, or chemistry doping. An international team of scientists led by Dr. Wenge Yang from Center for High Pressure Science &Technology Advanced Research (HPSTAR) presents a strong tricolor PL achieved in non-PL pyrochlore Ho2Sn2O7 through high pressure treatment. Interestingly the PL can be much enhanced after pressure release and recovered to ambient conditions. Their study is published in the recent issue of Physical Review Letters.