Yvonne Navarro coed @-@ wrote a novelization based on the original screenplay with Dennis Feldman . The book give several in @-@ depth details about the characters not seen in the film , such as Sil 's ability to visualize odors and determine harmful substances from edible items by the color . Gas appear black , food appear pink , and an unhealthy potential mate appear to give off green fumes . Other character details include Preston 's background in tracking down AWOL soldiers as well as the process of decoding the alien signal . Although no clues are given as to its origin , it is mentioned that the message was somehow routed through several black holes to mask its point of origin .