Color is mostly on occasion for works such as this (same with the usage of backgrounds and notebook paper instead of and index card). I do happen to have pictures of few of my index-carded ones on my computer (most recent is in color) as well as some works from my Art I made for classes. I might put a few of those on the Hub soon. The radio show is an old detective show in which the protagonist is an insurance agent who occasionally narrates the story through how he types up his expense account. I learned about it through the Sirius "Radio Time Classics" channel [I might have gotten the name wrong].

I have no idea, but it reminds me of some kind of detective show. Or investigator. Either way, you've done a really good job on this. I really love these kind of styles. The different uses of black/grey are perfectly well executed. :)