I used to have one of those Zefal in France (never had the need for it here
), it was good for about an hour. And the contenance was fairly small, less than 500ml.
White bottles would work best, but not sure if it would be any better than transparent.
I once put a water bottle in the freezer before a race on a hot day at Eastway, got it out well over an hour before the start and rode there, but it was still mostly frozen still at start time - I was frantically trying to warm it up under the hot water tap in the toilets! But if you time it right say for your second bottle you could have cool water after an hour's time.
If you have a Camelback and fill it with water from the fridge and ice cubes, it will stay fresh for longer. Will also keep your back cool, but makes it sweat more too.