
They don't have any problems together (cichlids and tetras) the problem is feeding the tetras
I think that if they cross will have only one copy of fading gene and the fry will be orange will pearls. To have white fishes you need 2 copies of the fading gene. It's simililar to the Ball python genetics - Pastel x Normal - 50%pastel & 50% Normal. Pastel x Pastel - 75% pastel & 25% super pastel.
Fader x Non fader - 50% fader and 50% non fader, Fader x Fader - 75% faders and 25% - super faders (white ones with red)