Begin query param checking; updates color selector on page load

This is a rough start to the ability to check the query string for a selected color. It required changing the `updateColors` function to expect a string instead of an HTML object.

The function takes the param after `color`, parses out any `+` signs and then updates the selector if one is there. This leaves the ability to use `custom` as a query param and you can do hex values in it.

You'll want to do something similar for the other dropdowns so that you can query them as well.

Finally, the way the `li`s are created there's a `#` being added to URL. Instead, you should update the URL with all the current parameters so you can share the current URL and all your presets easily.