<p>The ornamental fish industry faces challenges in enhancing fish coloration and health while simultaneously addressing the growing concern of agricultural waste management. This study investigates the potential of fruit and vegetable peels as feed additives for improving coloration, immune-related parameters, and growth in Banded gourami (<i>Trichogaster fasciata</i>), with potential for waste valorization in the food production chain. Over a 12-week feeding trial, the effects of banana peel (BP), apple peel (AP), carrot peel (CP), and beetroot peel (BRP) supplements at 5% dietary inclusion were evaluated on carotenoid content, immune-related parameters, and growth performance in <i>T. fasciata</i>. Fish fed supplemented diets demonstrated significant improvements across all measured parameters, with CP and BRP treatments showing the most pronounced effects. Specifically, total carotenoid content in fish skin increased by 218% in the CP group and 187% in the BRP group compared to the control. These peel supplements also elevated immune-related parameters, with CP and BRP groups showing increases of 120%, 133%, and 138% in lysozyme activity, respiratory burst activity, and total serum immunoglobulin levels, respectively, compared to the control. Additionally, growth performance improved substantially, with the CP group exhibiting 184% weight gain and a feed conversion ratio of 1.48, compared to 89% and 2.14 in the control group. These findings demonstrate the potential of fruit and vegetable peels as effective feed additives in ornamental fish aquaculture, with potential for waste valorization alongside improvements in fish quality indicators.</p> Graphical abstract <p></p>