Why are some teams wearing their road jersey's at home?

Just wondering why some teams are wearing their road jersey's at home this season? I understand it sometimes when the home team wears throwback jersey's, but this season I've seen teams use their road jersey's at home and the visiting team is wearing their white home jersey's.

It's not the first time they've done it. Usually it's because the home team is wearing a retro road jersey as you said but other times they might be fulfilling their quota for wearing their alternates, celebrating this or that etc. I'd say the exact circumstances vary each time you see it happen. In their opening night game of the 2006/2007 season, the Heat wore their red road jerseys against the Bulls despite being at home, since it was the jersey they had worn during the championship clinching game four months prior.