Any idea which episode it's from. That might be the only way to be sure.
It's 2.50:
Batman Displays His Knowledge.
I pulled out the Blu-ray and took a look at the episode and I'm sure it's one car. In the episode, the cars are the same colour (more bronze/brown than yellow), so either the yellower image is just a funny colour, or the HD master has been colour corrected.
The two images are taken moments apart from one another, with one short cutaway in between (Catwoman gets into the car. We cut to Batman telling Robin he's going after her. Then he leaps into the same car). It's all done in a studio, and the car can be seen sitting outside the doors for a good part of the scene leading up to this moment, which takes place indoors. I can't see any reason why they'd have needed a second car.
I'm a little sorry I got the Blu-ray out as now I've got another headache: the sound won't play on the episode, but it plays on the menus. I tried another couple of episodes and... same thing.
I also experienced serious sound problems with the
Wonder Woman Blu-ray set, so I think it must be a fault that occurs on WB BDs (a bit like the freezing with their crappy double-sided discs).