Grisaille (sometimes called Gray) was a member of the Spectrum Siblings, however he was created by Mr. Black, but not with Dame White. Because of this, he was disliked by most of the family, including his step mother. He acted as the primary agent to Mr. Black, although he punished him for whatever excuse he could think of.
In truth, despite having had the same traits as the family, he loathed his father and step-mother, and was eager to destroy the entire family.
Although he lacked the resources that Indigo had, he was more intelligent and personally powerful.