I'd love to have more darker ones. Right now I'm trying to isolate the brown ones after having an unusually large brown female from a friends brood give birth to more brown specimen. I kept back about 25-30, and about half look normal, half are quite brown.
Scorpions can come in alot of color variations as (speculation) an adaptation to survive in an ever changing environment. Sometimes brown is more successful, sometimes black is. It's truly fascinating.