Actually it is. You need a fertile SRT male and female. Of course not every fry will be SRT. Some will still be unfaded. You can also achieve SRT from just one parent being SRT and the other an unfaded. You then line breed for desired color, pearls, body shape etc...And I should also note, out of a huge batch of fry, you may only get 1-2 fish that would be considered high quality....Two high quality fish will give you high quality fry. There is no secret recipe.
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Judging from the way the OP posed his question it sounded like he was asking what 2 types of wish would yeild some SRT fry. That's why he asked what the formula was. Of course breeding 2 high quality SRT together would give you the best chance at SRT fry but try finding a fertile high quality SRT male.