Why are Blue Jeans blue?

How were Blue Jeans invented? What makes Blue Jeans different than other pants? How many styles of Blue Jeans are there? Attention SmartyFamilies! To get TWO NEW episodes of WHO SMARTED? every week, plus BONUS CONTENT all AD FREE (and support Who Smarted?)... subscribe to WHO SMARTED?+ Sign up HERE! Apple users can sign up right on the Apple App. (Free trial for either subscription!) For free home activities sign-up at www.WhoSmarted.com