Is this auto weight swapped or normal? Yellower than the movement

It’s got the older style pivot (or whatever it’s called) so I’d say if it was swapped, it’s period correct

There was a comment on a thread recently suggesting movement parts were often supplied in different hues.
However, I remember reading an essay (on Desmond’s site IIRC) noting that Omega took great care in matching the movement parts colour-wise.

Given that your rotor has the little circle and that it is a distinctly different colour it is likely a replacement.

Is it an issue?
Aesthetically perhaps but as @Davidt says, it’s the correct shape for the age of the movt.

So if you were to sell, a simple explanation of the colour difference should negate any negative feelings towards the colour variation.