Remember that the colour standards vary from colour to colour, with the scale of points differing, depending on the variety. There are even two pictorial ideals, one each for the two sexes. It is not easy. In the final analysis it becomes a matter of opinion. Set firmly within the framework provided by all I have mentioned above, but still a matter of opinion.
Different judges interpret aspects of judging differently.
Some penalize flecking very severely while others let some slight flecking pass. Still others are perhaps, too lenient with flecked birds. Spangle spots and Dominant Pieds' lack of spots are two other areas where judging can and does vary. I am being careful not to say which interpretation is wrong for it is not right for me to do so, yet I am a judge and have passed the BS test to become so. Others, some not judges, are not so reticent.