Sorry to break it to you, but that is false. The Citrus Pastel (as well as every other line of Pastel) is a line bred Pastel gene from that specific breeder. If you bred a Citrus Pastel to a Graziani Pastel, half would not be Grazi Pastel and the other half would be Citrus Pastel. You'd be mixing the both, which at that both, would not produce citrus or graziani pastel from that point on.
So with the Citrus gene, Amir, the producer of this Pastel line, got in a Pastel from Africa and line bred it to produce his own line of Pastels. Which he called the Citrus Pastel. Now when breeding out his Citrus Pastel's he noticed something funky going on which he called the Whiteout gene. This, to my knowledge, is not attached to EVERY Citrus out there. So to say that every Citrus produces whiteouts, is false.
So to the OP, when you mix Pastel lines, regardless of what line, you end up with nothing more than Pastel's and cannot market them as individual Pastel lines. You could, however, state what lines of Pastel they were bred from, which may appeal to some customers. But even then, though babies, would NOT produce Citrus or *other line* Pastels. It would be a combination of the two, with influences from both lines.