The definition of greige is a color somewhere between beige and grey.(noun)
When the clouds are turning a light beige-grey as part of the earliest onset of a storm, this is an example of a time when they are greige.
See greige in Webster's New World College Dictionary
Origin: Fr grège, raw (silk) < It (seta) greggia < VL *gredius, raw
See greige in American Heritage Dictionary 4
Origin: French grège
Origin: , from Italian (seta) greggia, raw (silk)
Origin: , from greggio, gray
Origin: , of Germanic origin.