This study performed the first on-farm attempts to quantify the utility of exposure to black substrates to improve prawn colour. Cooked prawn colour was tracked over time using subjective colour grade scoring and colour quantification from digital images. Results from subjective scoring showed that there was a significant difference in colour between animals that had been held in black bins compared with those that had been held on white bins (Table 5). However, the effect was quite small, only half a colour grade score, and was only observed in two of the three trials conducted after several hours of exposure. The difference in cooked colour was largely due to a loss of colour in animals held in white bins, and there was a general trend for all animals to become slightly darker during holding in the bins, regardless of the
colour of the bin