Monty Python

Thanks, Snoopy Actualy, the first question about the title still remains.

Hey guys! I am a big fan of Brandon's works. I don't live in an English-speaking country and not all of his works are currently translated into my native langiage, so I have to read them in English. Reading Skin Deep I had a few moments where neither online nor offline dictionaries could help me catch a picture. I appreciate if anyone of you can explain the following words/idioms. First the title of the book itself - Skin Deep. I know that the general meaning is superficial, on the surface, external, outward, shallow, empty, meaningless, but I didn't quite understand how it correlates with a story. Second: What is exactly that red dye #6? Why is it supposed to be fake? Is there some direct meaning or not? Thanks in advance!