Don't want a "guarantee." I am quite confident that normal Pastels WILL brown out regardless of how bright they are as hatchlings and how long they retain the color (it's just a matter of degree).
Just wanted it clear that getting the brightest color baby ever from the brightest color parents ever that have retained their colors for the longest is NOT a guarantee that the hatchlings or the parents will keep those colors...
However much I wish it were.