Not So Pretty in Pink: Computational Modelling of Cricket Ball Visibility with Colour Vision Deficiency

BACKGROUND: Day-night test cricket uses a pink ball that players have reported as less visible than the traditional red ball, particularly at dusk. Around 9% of male cricketers have a colour vision deficiency (CVD), yet how CVD interacts with ball colour and match conditions is unknown. OBJECTIVE: To investigate the degree to which protanomaly ('red' deficiency) and deuteranomaly ('green' deficiency) affect the visibility of different coloured balls in professional cricket. DESIGN: Mathematical modelling. METHODS: Spectral reflectance of new and old red and pink balls was measured in the laboratory. Spectral measurements of backgrounds and illuminance were gathered during a day-night match at Lord's Cricket Ground (London, England) at day, dusk and night. Luminance contrast of the ball relative to the background was calculated for each combination of ball, time of day and background surface for a typical observer and for observers with CVD. RESULTS: Across all backgrounds and lighting conditions, ball visibility varied by colour, ball age and observer type, with the old pink ball being the most problematic, particularly for observers with deuteranomaly and typical observers at dusk, and for observers with protanomaly against the crowd and grass. Notably, observers with protanomaly sometimes experienced enhanced contrast, especially against the pitch and dusk sky, where more severe CVD paradoxically improved visibility of the old pink ball. CONCLUSIONS: The pink ball may disproportionately affect cricket players with CVD. On balance, the red ball affords the most consistent and equitable visibility across match contexts.