Color Wheel Diagram with Labeled Sectors and Central Sigma Circle #1766281 (License: Personal Use)

This black-and-white diagram depicts a circular model divided into three primary sectors labeled r (red), g (green), and b (blue), converging at a central point. Inside the main circle sits a smaller concentric circle marked σ, possibly representing luminance, saturation, or a neutral core in color space models. The clean, geometric layout suggests use in educational or technical contexts involving color theory or signal processing.

Typically used in academic or technical web pages explaining color models (e.g., RGB, HSV), computer graphics, or image processing algorithms; matches user intent for learning foundational concepts in digital color representation.