Multicolored Tanagers are canopy omnivores, primarily consuming ripe fruits, supplemented with insects and other arthropods (Hilty 1985, Hilty and Brown 1986, Lentijo and Kattan 2005, Raven et al. 2008, Fierro-Calderón and Johnston-González 2014). Specific documented fruit items include arils of Tovomita, small Ficus fruits, green berries, and flower clusters (Miller 1963, Isler and Isler 1987, Fierro-Calderón and Johnston-González 2014). They have been observed feeding fledglings melastome fruits, and they are known to be an important consumer and potential seed disperser of Cecropia telealba, Miconia theizans, and Aniba muca (Ríos 2005, Kessler-Ríos and Kattan 2011). When solitary or in small family groups they eat fruits about 87% of the time, arthropods 13%, whereas in mixed-species flocks they eat fruits (91%) slightly more often and arthropods (9%) slightly less (Kattan 1992). More specific reports of arthropods include small larvae and a caterpillar (Isler and Isler 1987).
The Multicolored Tanager typically forages in the sub-canopy to canopy of large tracts of pristine mature forests (Isler and Isler 1987, Marín-Gómez et al. 2009, Fierro-Calderón and Johnston-González 2014). Contrarily, Willis (1988) reported them lower in the forest strata, foraging from 2-10 m and often in the understory. In Valle, most foraging observations (n=50) occurred in the crowns of trees, with a mean foraging height of 10 m, rarely foraging as low as 4.5 m (Isler and Isler 1987). They actively forage for insects and other arthropods by searching foliage, gleaning from the undersides of leaves, reaching up at times, hanging at others, by peering and running along limbs, probing tangles of moss and bromeliads, and never staying in one place long (Hilty and Brown 1986, Isler and Isler 1987, Ridgely and Tudor 1989, Angarita and Renjifo 2002, Restall et al. 2006, Raven et al. 2008, Marín-Gómez et al. 2009). They typically emit a constant chatter while foraging (Isler and Isler 1987, Marín-Gómez et al. 2009). Local migrations may be associated with fruit availability (Fierro-Calderón and Johnston-González 2014).