This is my theory. I've noticed there has been a ton of Electric blue fish being produced. EBJD, Electric Blue Rams etc. Which makes me believe that the "electric blue" is a recessive gene and not created through hybridization. Simple genetics would be to line breed until the recessive trait is acquired.
I believe the first Thai Silks were made some 20+ years ago.. Like the EBJD, they had some genetic issues and were an unstable strain.