I have an inferno female that surprises me with each shed, she looks just as good if not better than when I got her. In all fairness she is only 400 grams though so it's too early to say for sure but I have definitely seen other morphs going down hill by this size so she's off to a good start, only time will tell if she holds this pretty into adulthood. As for hgw by itself, I have no experience with it.
Others that have held color well for me are:
enchi pastel 900g
killerbee 800g
nuclear enchi 1000g
bumble belly 1800g
pastel desert ghost 1100g by far my favorite! After each shed she looks just as clean and bright as ever! Desert ghost is an amazing morph, in combo it will make any other morph look amazing. I can't believe more people aren't working with it. I have big plans for this girl.
I've been very lucky with all my choices so far, I've only had a couple dull with age so far but I still have quite a few that are too young to tell but I have high hopes because most combos that are still growing out have fire, enchi and OD in the mix so I think my odds are good.