Yup, hatchlings go from a grey-black coloration to yellow-black colorations rather quickly. Most do a complete change in the first 4-6 months, and after that they continue to get brighter until for the next few years.
When they get old age the brown sorta takes over the yellow (to my knowlege...) A few rare specimens have retained the yellow over their entire lifetime, but it is rare.
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Current Collection:
0.1 Antherystic elaphe guttata guttata - Corn Snake
1.0 Elaphe vulpina gloydi - Eastern Fox Snake
0.1 Elaphe obsoleta obsoleta - Black Rat Snake
0.1 Leucistic elaphe obsoleta Linheimeri - Texas Ratsnake
1.1 Morelia spilotac cheyni - Jungle Carpet Python
0.1 Tiliqau scincoide - Blue Tongue Skink