Switzer, Robert and Joseph

DayGlo fluorescent pigments, a new class of pigments based on fluorescent dyes and polymeric materials, were developed between the 1930s and 1950s by scientists at Switzer Brothers, Inc. (now Day-Glo Color Corp.). These pigments absorb various light frequencies (visible and invisible to the human eye) and reemit them, producing intense visible colors that appear to glow, even in daylight.