think it might be red vs blue
I think GL is trying to fool us like he did on ROTJ
On the teaser trailer, anakins lightsabre glow doesnt look as good as obi's, but the closeup of him choking obi its lukes saber from ANH,
So what I'm thinking is that (sorry if this has already been said) ani uses his old one (blue) on the table fight and later somhow obi manages to take ani's lightsabre or ani just decides to put it away, and takes out his brand new sith lightsabre