FIFA is tampering with Club World Cup ticket sales to try and make poorly selling games appear full on TV broadcasts.

That's just amateur hour. Just try to avoid showing the crowd at all and flagrantly lie about attendance figures, like MLS.

So, is blue what's available or what's sold?

Either way, how do you mean tampering? Agreed they likely put those areas on sale first, to help with how it looks on TV, but that's not that uncommon I don't think?