Quill's and Charlie's people both see each other as the bad guys; Quill says that her people were freedom fighters against an oppressive regime, while Charlie states that his people were trying to stop terrorists. Considering how Charlie is royalty while Quill calls herself a soldier, their situation can be seen as a class/race war.
It also explains why Tanya, who is black, is the sole person to relate to Quill.
The pilot has Quill making a snarky comment about Downton Abbey, which prompts April to state that she likes the show. Tanya quips that of course she would like it, seeing as how "it's about white people being nice to each other." Ram then snarks that Tanya would only watch it if Idris Elba was on it. Now, anyone who has seen Downton Abbey knows that Tanya's statement is inaccurate, but it makes sense with Ram's remarks: Tanya doesn't like that there aren't a lot of black people on it, so she ignores the show and therefore doesn't really know what the show is about.
It also foreshadows a later conflict with April, when she accuses April of having easier problems due to her being white.
Finale spoiler: The Weeping Angels feed off time energy. Well, guess what Coal Hill is known for...