I would definitely pass on this. The pictures are overexposed, which is a good trick to hide defects.
Even knowing this, the dial seems dirty - if you look around the Omega logo, there is some uneven staining, similar to around the 3 o’clock marker, below the hands as well. Maybe some water intrusion in the past, who knows. The various spots (plus all the ones you don’t really see) could make it look “dirty”. Surely less appealing than on pictures.
The case has also plenty of dings - look at 1, 10 o’clock, the lower right lug and the scratches on the other lugs. Pretty prominent, even if overexposed. Needless to say this will bother more than one pretty quickly.