A spiropyran derivative containing an acridinium and a phenoxide moieties was found to exhibit both halochromism and electrochromism in response to acid stimulation and oxidative stimulation, respectively. Variable scan-rate voltammetric studies revealed that the acridine spiropyran undergoes a reversible conversion between a closed-ring and an open-ring form during the redox cycle. The presence of a ring-opened radical cation species was demonstrated by simultaneous electrochemical ESR measurements.