There are designer stuff like Ben Stegall with 'the sickness' GTPs which are black, green, yellow and blue. He actually just had a clutch of them and the list is longer than the number of animals he has available lol. I would be careful of so called blue line. Adult female GTPs can become blue when they are gravid and will hold that hormonal change for a while. There are true blue ones though but they command big dollar.
Thing about GTPs is they vary greatly. So just because the parents look one way doesnt mean the babies will. Generally red neos will develop more blue assuming its a northern but that is generally, not a guarantee. Also certain locales will have certain traits like Sorong type and Jayapura type will generally have a blue dorsal stripe. And no southern locales are blue. Those are white like Aru unless they are a cross
Just be prepared to shell out serious cash for a designer morph. I've seen them from $2500-5000+.