This looks like a cool project, but I don't know how I feel about the non-primitive type loaders. Date strings, email addresses, urls, colors, and lat-long are hard problems, and trying to handle them in the spec is a misstep. Leave the complex loaders out, strive to handle perfectly just the core list of primitives, and let devs write their own email or url parsers. (Who is asking for lat-long parsing?)
(Seriously, the email parser doesn't match most of the Examples [0] on the Wikipedia page about email validation. Don't use regex to validate unless you're gonna write `/.* @.*/`.)