I actually did notice this, and it surprises me not a lot of other people noticed. While I do not use Lumine in my team, during quests, or cutscenes I noticed her flower was (for example in inazuma) purple. I went to Fontaine to confirm the sudden color change in the flower, and surely, it was changing colors. This brings up many questions in the Travelers elemental powers, and how they can wield them without a vision. But, good job devs. Amazing detail.
