No, this won't work the way you want it to. Insight triggers when the spell is cast, but by the time you get a chance to respond with Blind Seer 's ability, that moment has already passed. It won't trigger in your example if the spell wasn't already green to begin with.
July 27, 2019 11:21 p.m.
In the future, please remember to hit the green “mark as answer” button to indicate your question has been resolved. Since this question has been answered for a couple of days with no follow-up questions, I have gone ahead and marked an answer on your behalf.