Eyeshadow colors that flatter brown eyes best, according to the website Makeup Geek, are opposite colors. Purple and teal are the best eyeshadow colors for brown eyes, because they contrast with brown eyes.
Brown eyeshadows also are acceptable, as long as they are peachy or have a silvery undertone like taupe. Eyeshadows with too much brown diminish the look of brown eyes. Another way to accent brown eyes with brown shadow is to pair the shadow with green, purple or teal in the lower lash area.
Silver and blue eyeshadows, according to Makeup Geek, work well with brown eyes. However, these shades should not be placed underneath the eyes, as they can accentuate dark circles.