Background <p>Color and patterns in animals are closely tied to reproduction and survival, and have long been of interest to evolutionary biologists. For instance, bright conspicuous coloration plays a vital role in aposematic organisms as these phenotypes help communicate to potential predators that they are chemically defended and therefore unpalatable. Although the field has made significant progress in identifying genes associated with the production of conspicuous coloration, our knowledge of the genes associated with carotenoid metabolism and their roles in pigmentation is incomplete. Here we attempt to fill this knowledge gap by investigating how dietary carotenoid and retinol availability affects levels of gene expression and color formation in two color morphs of the mimic poison frog (<i>Ranitomeya imitator</i>), the orange-banded Sauce morph and the red-headed Varadero morph which exhibit bright orange and red coloration, respectively.</p> Results <p>We found that froglets raised under a carotenoid/retinol-enriched diet showed elevated expression levels of genes associated with the retinol pathway (e.g., <i>dhrs3</i>,<i> pnpla3</i>) whereas froglets raised under a carotenoid/retinol-deficient diet showed elevated expression levels of genes associated with the retinoic acid pathway (e.g., <i>aldh1l1</i>, <i>aldh6a1</i>,<i> cyp7a1</i>). In addition, we found that froglets raised on a carotenoid/retinol-enriched diet displayed brighter skin and higher ratio of bright colored to black skin patches when compared to froglets raised on a carotenoid/retinol-deficient diet in both the Sauce and Varadero morph.</p> Conclusions <p>The genetic basis of carotenoid metabolism and its role in pigmentation remain poorly understood in amphibians. Our results provide insights into the key genes associated with carotenoid/retinol metabolism and their roles in pigmentation which should be investigated further and experimentally manipulated.</p>