Insect body colors and patterns change markedly during development in some species as they adapt to their surroundings. The contribution of melanin and sclerotin pigments, both of which are synthesized from dopamine, to cuticle tanning has been well studied. Nevertheless, little is known about how insects alter their body color patterns. To investigate this mechanism, the cricketGryllus bimaculatus, whose body color patterns change during postembryonic development, was used as a model in this study. We focused on theebonyandtangenes, which encode enzymes that catalyze the synthesis and degradation, respectively, of the precursor of yellow sclerotinN-β-alanyl dopamine (NBAD). Expression of theG.bimaculatus(Gb)ebonyandtantranscripts tended to be elevated just after hatching and the molting period. We found that dynamic alterations in the combined expression levels ofGb’ebonyandGb’tancorrelated with the body color transition from the nymphal stages to the adult. The body color ofGb’ebonyknockout mutants generated by CRISPR/Cas9 systemically darkened. Meanwhile,Gb’tanknockout mutants displayed a yellow color in certain areas and stages. The phenotypes of theGb’ebonyandGb’tanmutants probably result from an over-production of melanin and yellow sclerotin NBAD, respectively. Overall, stage-specific body color patterns in the postembryonic stages of the cricket are governed by the combinatorial expression ofGb’ebonyandGb’tan. Our findings provide insights into the mechanism by which insects evolve adaptive body coloration at each developmental stage.