Of a bluish grey color.
having a deep purplish-blue colour
A purplish-blue colour
An indigo-colored dye obtained from certain plants (the indigo plant or woad), or a similar synthetic dye.
An indigo plant, such as from species in genera Indigofera, Amorpha (false indigo), Baptisia (wild indigo), and Psorothamnus and Dalea (indigo bush).