Intense Blue (Phthalo Blue) is a deep intense blue which when undiluted, forms an inky blue-black. It is made from the modern pigment Phthalocyanine which was introduced in the 1930s.
Hooker's Green Dark is a rich dark green with a blue tint. A mixed pigment colour, it was originally created by 19th c English botanist illustrator William J Hooker.
Ultramarine is a rich deep transparent blue. It was created by French chemist Guimet in 1828 as a synthetic but chemically identical replacement for the expensive pigment derived from Lapis Lazuli.
