In the traditional view of sexual selection, females are the choosier sex, and males of many species often develop exaggerated ornaments. Recently, however, the evolution and maintenance of female ornaments has also attracted significant attention. In the present study, we examined the function of a female ornament, i.e., red coloration of the area around gill cover, in the context of male mate preferences in the cyprinid fish Puntius titteya. The result of a dichotomous choice experiment showed that males preferred females with redder coloration. Together with the results of a previous study, these findings suggest that males and females in this species mutually select each other based on red coloration. In addition, females with higher color saturation spawned larger eggs. With supplementation of carotenoid-rich foods, females exhibited redder coloration and higher color saturation. These results imply that, by choosing females based on carotenoid-based coloration, males might obtain high quality mates and offspring.