entertaining chemistry problem

I'm supposed to be working on homework and it's very late, so this isn't a really blog post, but I came across this problem in my chemistry textbook, and had to share.

• In a game of "Clue," Ms. White is killed in the conservatory. You have a device in each room to help you find the murderer--a spectrometer that emits the entire visible spectrum to indiciate who is in that room. For example, if someone wearing yellow is in a room, light at 580 nm is reflected. The suspects are Col. Mustard, Prof. Plu, Mr. Green, Ms. Peacock, and Ms. Scarlet [I must say that I appreciate their use of Ms. instead of Mrs. or Miss]. At the time of the murder, the spectrometer in the dining room recorded a reflection at 520 nm, those in the lounge and study recorded reflections of lower frequencies, and the one n the library recorded a reflection of the shortest possible wavelenght. Who killed Ms. White?

Obviously, this has a lot of problems as a persecution scheme (also, who said that Col. Mustard always has to wear yellow, Mr. Green always has to wear green, and so forth? And clearly it can't be Mr. Green, because both of the Mr. Greens I know of (John and Hank) are clearly excellent, non-murdering, made-of-awesome type people), but it's such an adorably transparent attempt to make this homework interesting that it makes me happy.

Also, now you know how to commit murder. Just wear a color that has nothing to do with your name. And WHAM! You're safe. 

[I just discovered that it's part of my homework assignment! YES!]