The Plain-colored Tanager eats both fruits and insects (Isler and Isler 1987). When foraging, it comes lower in the tree for fruits in 3-5 mm in diameter (Isler and Isler 1987). It mostly feeds on fruit, and takes a wide variety, including fruits of Tetracera, Lantana, Hamelia, and catkins of Cecropia. The most favored fruit may be Crecropia (Isler and Isler 1987). The Plain-colored Tanager feeds more on insects and spiders during the breeding season (Isler and Isler 1987).