We shouldn't take the colours being inverted as they are. They represent the girl's current state of mind; here everything she has ever believed in - asking boys out, buying a simple coffee and even her work - is being slowly destroyed by the appearance of Marten and Dora. She realises that no matter she does in life she shall find heself reminded of those two, slowly torturing her; constantly playing out her mind that she was threatened with a sword, she caused a couple to argue over TWO comic pages, making the readers having to sit through it and thus she has decided to give up on her sanity.
Tomorrow's comic: she slashes her cat's throat and paints her walls with his remains, laughing hysterically, her eyes bloodshot and her state of mind completely destoryed.
Thanks, mate. Good comic!