Curate, connect, and discover
Yeah maybe the curtains are just blue but maybe the author likes that you see that as symbolism for sadness. Have you ever thought of that? Maybe writers like when you find meanings in their works that they didn't think of. Just because it wasn't intended doesn't mean it can't be true.
Over analyze everything. Find meaning where there was nothing before. We found God in the stars, we can find meaning in the curtains.