Hi mat.si,
my own juveniles have always displayed a similar, but less pronounced colouration as the adults.
Male juveniles;
Bodies have always been shades of brown, from a beige to a dark brown. The head being somewhat darker even charcoal grey in colour. Occassionally a darker dorsal stripe down the lentgh of the body, starting from the nape to the tail tip.
Female juveniles;
Head and bodies in general an overall charcoal grey, light grey, white blend. Often alternating light dark down the length of the body. Head dark, body lighter, with varying markings.
I had two original pairs, from different sources, offspring from both couples produced identifiable juveniles of similar ilk. Unlike yourself I manged a 3:2 ratio in favour of males.
Sorry no pics readily at hand, computers are new, I'm old, pictures on slide film.
best of luck for the rest of the breeding season