Color to HSL

Color to HSL converts the incoming RGBA color into the HSL color model by extracting three perceptual properties:

• Hue identifies "what color" it is on the circular color wheel, normalized to 0 — 1. Pure red = 0, pure green = 0.333, pure blue = 0.667, and the value wraps back to red at 1.0.
• Saturation measures how vivid or muted the color is. A fully saturated color has maximum chromatic intensity; a desaturated color appears gray.
• Luminosity measures perceived lightness. Black = 0, the purest expression of any hue = 0.5, white = 1.

For achromatic colors (grays, black, white), Hue is 0 and Saturation is 0. Only Luminosity varies.

• Hue-based branching — Use Compare nodes on the Hue output to detect whether a color is in the "warm" range (0 — 0.15 or 0.85 — 1.0) or "cool" range (0.4 — 0.7).
• Saturation filtering — Detect desaturated regions (Saturation < 0.1) for conditional effects.
• Brightness extraction — Use the Luminosity output as a simple brightness measure to drive other parameters (e.g. particle spawn rate proportional to scene brightness).
• Color analysis — Decompose a dynamically generated color to display its HSL values in a UI Text overlay for debugging.
• Hue shifting — Decompose with Color to HSL, add an offset to Hue using a Math node, then recompose with HSL Color to shift colors around the wheel.

• The Hue output is circular: values near 0 and values near 1 are both red. When computing hue differences, account for this wraparound.
• For pure white, pure black, or any shade of gray, Saturation will be 0 and Hue will be 0 (undefined). This is expected.
• Pair with HSL Color for a decompose-modify-recompose workflow.
• To decompose into RGB channels instead, use the Color to RGB node.