Why is identifying a Super Yellow Belly often difficult without pedigree information?

The difference between single-gene and two-gene expression can be subtle

A Super Yellow Belly is the homozygous form, meaning the snake possesses two copies of the co-dominant Yellow Belly gene. While this two-copy state is expected to produce an even more pronounced visual effect than a single-gene carrier, the text notes that without established lineage documentation, discerning this difference in isolation can be genuinely difficult. This ambiguity arises because the enhancement provided by the second gene copy might only be a subtle intensification of the already bright yellow belly and clean sides, making visual confirmation unreliable unless comparing side-by-side with a known single-gene animal or possessing confirmed parental history.