ORIGINAL: OzMo
All natural rubber is sensitive to sunlight. The lighter colored bands are the same as the darker colored ones (usually) but are FRESHER. They do have a shelf life. I keep my flight box stash in a brown paper bag inside of a zip lock baggy. No sun damage. I get my #64s at an office supply store. But the darker opaque looking ones I leave on the shelf. Only buy the nice lite brown or tan pastel colored ones. I also hide a tupper ware container with a paper bag and some #64s at the field ...cuz I forget to refill my flight box stash sometimes.
What I am referring to I find to be consistent across stores and time. In the attached pic the Office Max band is on the left. The Staples is on the right. But we agree that the lighter band is the better one.