This is an example of Analogous. In this illustration, the artist used yellow , red , yellow –red and it tints and shades to create artwork. Yellow and its tint seems to be colour that make the art work stand out.
Delphinium.. These tough perennials bloom in early summer and sometimes again a couple of months later. Mature height can average anywhere from 2 to 8 feet tall, depending on variety; the flower stalks need staking on the taller types. Delphiniums are heavy feeders; plant in deep, rich soil. They also prefer cool summers and can't stand up to heat and humidity. USDA Zones 3 to 7