It almost looks like they were bleached. How are you growing them? Are they outdoors in sunlight like it looks in the pictures? Or are they inside under artificial lights?
Are you giving them any food? What kind of soil?
I guess you could just tell people you are growing Acapulco Gold! You've stumped me with that. I would guess some sort of nutrient difficiency, but I don't know what, never seen that before.