Confused By Colors Of Java Sparrows.

Question:
In my aviary I have two pairs of Java sparrows, of which one pair is a
white cock and a normal hen. The two pairs have just produced the following
chicks, which I am a bit onfused about because I though that they would be
white or normal : 3x white with grey on the chest; 3x fawn with red eyes;
4 x fawn and grey; and 2 x normal looking. The parent don't have red eyes.

Answer:
Unfortunately there is insufficient information to fully answer your question.
Looking at the outcome from your two clutches, I am guessing that your
two pairs of Java sparrows are housed together in the aviary. The problem is
two fold in generating a meaningful answer. Firstly if the two pairs are housed
together, there is no assurance that all the eggs in a clutch have been fertilized by the mate. It is perfectly feasible that the supposed mate only fertilized a proportion of the eggs, the remainder being fertilized by the other male; equally, the one male could have fertilized all the eggs in both clutches.

The other problem, irrespective of whether or not the two pairs are housed together or separately, is that pairings involving white Java sparrows do not follow the standard rules of genetic inheritance. Thus, greys mated to whites will, ordinarily, produce young, the majority of which will be white, with some greys also possible and whites with grey areas likely.

_{source Bird Keeper Mag.}