The flames represent Fawna's feelings; more especifically her link to anger. Killer Trait is first a mystery thriller and second a romance, which is why the flame choices aren't associated with raising affection but rather with which path Fawna will end up in in her quest for revenge.
Choices where she's more sweet or forgiving are represented by the green flame. Choices where she's more chaotic or explosive are represented by the red/orange flame. And choices where she's more icy/cold or cares more about her job are represented by the blue flame.
How each of them will impact the story... you'll have to wait and see! 馃槈
