It kind of is.. but IMO the drivers are new, stiff, and need the workout. And it's not 100% continuous, it's 10 minutes brown followed by 1 minute sweep, then 10 minutes pink & 1 minute sweep, then 10 minutes white & 1 minute sweep then 10 minutes violet & 1 minute sweep, & repeat. All tracks contain a few seconds of silence at the end, it's decent.
I can't think of a song that is perfectly balanced. Does it contain all frequencies? Perhaps. But are they equally represented or will it work the mids or lows more or less than the highs?
With colored noises you know exactly what you get: brown for low & low-mid workout, pink & white are balanced, violet is for highs. If brown plays as much as violet, both extreme ends of the spectrum receive equal attention.
LE: I'd be curious to know Bob's method, or how a manufacturer does it in-house.