That sounds like very fancy water! I don't have any experience with using blue glass, but I would think it should be fine - better than plastic for sure. I'm sure someone will come along and correct me if I'm wrong before long. But, would putting the bottle in an old sock or something work if too much light gets in through the blue?
I don't know for sure either, but I would think the darker the better. At least it would be better than clear glass and better than plastic definitely. I know which bottles you are talking about. Very good idea and one I'm inspired to copy. I wish beer bottles had screw on tops... Wondering which other booze bottles I could use!
The supplier I get my nicest EOs from always uses cobalt blue glass bottles. She's pretty particular about maintaining quality, so if blue glass was not good enough she wouldn't be using it. If that's any indication I think your idea is spot on good!
One of the bigger aromatherapy brands over here sells everything in blue glass packaging on account of it protecting the product so it seems like you might be onto something! I just like the look of it in my bathroom lol