If one can write grim dark or noble bright, then why can’t I write other combos?
I’m not certain this is a four-variable combinatoric. If each of grim, dark, noble, and bright were on-off switches, we could have genres like
If fiction is a meta truth, at times, then a story might have all these elements. Yang and yin and so on. Why couldn’t the tone of a story change along the way? (The writer changes.)