Coolwarm

Coolwarm is a diverging colormap often used in data visualization. It is designed to represent data with a distinct neutral midpoint, typically zero, and transitions through contrasting cool and warm colors to represent values above and below this midpoint. The cool colors, usually blues and greens, are used for lower values, while the warm colors, typically reds and oranges, are used for higher values.

The specific color progression in Coolwarm is intended to provide a clear visual distinction between positive and negative deviations from the central value. This makes it particularly useful for displaying data such as temperature anomalies, financial gains and losses, or any dataset where a zero point is significant and deviations in either direction need to be easily discernible. The gradual transition between the cool, neutral, and warm segments helps users to intuitively understand the magnitude and direction of the data.

Coolwarm is part of various scientific visualization libraries and software packages, making it a readily accessible tool for researchers and data analysts. Its effectiveness stems from the human perception of color, where blues are often associated with cold and reds with heat, making the colormap's intent immediately understandable. This perceptual mapping aids in quicker and more accurate interpretation of visual data.