[OC] North American Gulls on the Kodak Gray Scale

To simplify the infinite gradient between white and black, the Kodak Gray Scale is often used to describe the color of a gull's upper parts. Adult gulls of each species have a range of variation in "upper parts," though it typically lays within 2 steps in the Kodak Gray Scale. Photos included for each gull are illustrative and shadows / lighting conditions may differ slightly from the KGS grays shown.

Source: The Gull Guide (Amar Ayyash), species account introduction with KGS ranges listed here

Tool Used: PowerPoint