The trait is dominant I believe.
As for what you are looking for, this is from NERD's website:
This beautiful mutation shows a lot of variety - from light, burnished gold animals with high white laterals & thin pattern, to deep, rich coffee brown snakes with thick webbing & minimal white sides, not to mention everything in between! Spiders also possess slatey green eyes, black moustaching on the upper lip and funky head patterns that vary as much as each individual animal. Spiders tend to be strong feeders & strong breeders, and have what many keepers consider an outgoing personality that seems to be genetic. The Spider has also proven to cross extremely well into other color & pattern morphs, resulting in many gorgeous & popular designer combos, with new additions every year.