This study investigated the effect of dietary paprika on the skin coloration of red- and white-colored fancy carp Cyprinus carpio var. koi, in two age groups: 0-age (7.4±0.1 g/fish) and 1-age (164±2.9 g/fish). Three isonitrogenous diets were formulated to contain 0, 5, and 10% paprika (Con, P5 and P10, respectively). Three replicate groups of 0-age fish and two replicate groups of 1-age fish were fed one of the experimental diets for 9 weeks. Survival, weight gain, and feed efficiency were not significantly affected by the dietary paprika level (P>0.05) at both fish sizes. The dietary paprika level influenced the redness (a*), lightness (L*), and yellowness (b*) of fish skin. The L* value of the skin of the fish fed the P5 and P10 diets tended to decrease with feeding period. The skin a* value of 0-age fish (small) fed the diets containing paprika increased significantly with feeding period and was higher than that of fish fed the control diet after 3 weeks (P<0.05). However, the a* value of 1-age fish (large) fed the diets containing paprika tended to increase slightly with feeding period. At the end of the experiment, the skin total carotenoid level was increased significantly in fish of both sizes fed the P5 and P10 diets compared to fish fed the control diet. Therefore, 5% paprika powder in the diet increases the skin redness of red- and white-colored fancy carp, especially in small fish.