10. The Hint That Kylo Is Fully Dark Side Now
Though JJ Abrams gets a lot of grief for his use of light - or flares, more specifically - he did use it masterfully to help the narrative of one of the film's most emotionally loaded sequences. As Kylo Ren faces his father, one half of his face is swathed in red light, and the other in blue. At that point, his allegiance is unclear, but as the sun disappears and Ren kills Solo, his face turns completely red. That's not only a clever hint at his transition (because there really can't be a way back for him), but also reflects how the original trilogy used light to symbolise the duality of good and bad.