It could be the amount of yellow but if you're saying its more pastel Butters could have influences of White & Yellow.
Yeah, its going to be typical to find that though. They strive for the 'same experience in any location' but will never achieve that because of the people that are hired in each store. That is why I support my local mom and pop store that have their children running it and each one is into the departments that they sell items for. Two are into reptiles, one or two are into fish, and the other one is into small animals, then they have a employee there really dedicated to birds.
Just pulled this from the Wiki:
"A High Yellow Leopard Gecko shows a vast amount of yellow on its body with reduced black spotting. When Leopard Geckos were first introduced into the United States, the only morphs available were Normals and High Yellows.
Genetically speaking, High Yellows are a line bred trait."
So there it is, the amount of yellow and reduced spotting. Considering he has little spots on his back, I would say a Hypo High Yellow.