If you check out the following website you will see that there were girls named Magenta born in the state of Oregon in both 1988 and 1996. Though it's rare, I have seen other examples.
http://www.dhs.state.or.us/publichealth/chs/babyname/babyname.cfm
Of course almost any name that's been featured in a popular film will have at least one real child with it somewhere, though they may have been born after the film was released and have been inspired by it. :)