The short answer is both are correct, as stated above some manufacturers have different rules for paint.
The more subtle answer is that some dealers will allow you some paint that the manufacturer has decided isn’t included, others won’t for the same car.
It’s all part of the decision making process, do you want a specific colour for that car and would that unavailability be a deal breaker. Is there another car that you also like but are happy in a choice of available colours?
I'm Autistic, if I say something you find offensive, please let me know, I can guarantee it was unintentional.
I'll try to give my honest opinion but am always open to learning.
Mark