Marketing language is simple, but loaded with meaning.
Here's what that slogan can mean:
"in the past, things were cool for all sorts of reasons, but perhaps those reasons were superficial, as they did not relate to the usefulness of the object. Now, we have a new trend, of liking things that are useful, and everybody wants things that serve a great purpose'
This phrase plays on the idiom 'color x is the new black'. i.e. 'red is the new black'
That idiom means 'for a time, everyone wanted black things. the majority of men in the office, for example, were wearing black shirts. Black was the standard, and it seemed that everyone wanted black. Then all of a sudden, people changed their thinking and everyone wanted red. Now everyone is wearing red shirts - how did that happen? Nobody made this decision, it made itself. But amazingly, all the people you can see wearing red, unconsciously followed this new trend.