What color are the girl's eyes? SPOILER: The exact same shade of gray. The left one just appears turquoise due to your eyes playing tricks on you. *waving sharp pencil at eyes* I warned you two about that!
The girl's right eye only looks the same as the turquoise hair clip because of the reddish context. Part of the process of seeing color is that three different kinds of photoreceptors in the eye are tuned to three overlapping families of color: red, green and blue (which are activated by visible light of long, medium and short wavelengths). These signals are then instantaneously compared with signals from nearby regions in the same scene. As the signals are passed along to higher and higher processing centers in the brain, they continue to be compared with larger and larger swaths of the surrounding scene. This "opponent process," as scientists call it, means that color and brightness are always relative.
I mean, neat, but who cares about the girl's eyes? Just look at those fingers, clearly this girl is a vampire and needs a good wooden staking through the heart. You do it though, blood makes me squeamish. Plus, you know, maybe she's just a regular girl who misplaced her nail clippers.
Thanks to Sarah, who doesn't believe in colors. Me neither, or smells.