ChromaSol
ChromaSol looks at a photo, isolates the people, leaves skin out and reduces the clothing to its true colors: one color per garment. It then searches the 348 combinations of Sanzo Wada's "Dictionary of Color Combinations" (1933–1934) for the closest one.
All on the phone
No server, no accounts, no network: no photo leaves the device. Available in English, Spanish and German, following the iPhone's language.