ColorSutra claims to take the guesswork out of "matching colors" so the idea of using my iPhone (with its built-in camera) as an color matcher was a compelling one! After downloading the application ($1.99), I decided to reach out to ColorSutra's developer, Alex Rybkin, to find out what the application really did and how it worked.
According to Alex, "ColorSutra provides assistance in finding colors that match (or go together with) any chosen color. A typical use case would be if you want to color-coordinate your clothes, and try to pick a tie that matches your shirt". I also learned that ColorSutra will not mix paint for you (as they do at Home Depot), but an interior designer may find it useful when creating color schemes for an interior decorating project.
I am by no means a color expert (my wife would tell you so), but Alex assured me that the algorithm that ColorSutra uses to calculate matching colors is based on the work of Swiss artist/scientist Johannes Itten, who developed the field of color harmonies (sometimes referred to as "color theory"), so it all seems scientific enough.
I found ColorSutra intriguing after playing around with it for a while, but realized it was one of those applications that is going to appeal most to the people who really need it. So if you challenged from a "color matching" perspective, ColorSutra may definately be the app for you!