Niagara Falls Color: White-Green Shimmer from Light, Mist, Minerals

Niagara Falls has no intrinsic color. Its appearance is a dynamic optical effect:

• White: Aerated, turbulent water scatters all wavelengths—foam, mist, spray.
• Pale green/blue-green: Dissolved minerals (limestone/dolostone bedrock → calcium/magnesium carbonate) + selective absorption of red light by water.
• Rainbows: Sunlight refracting in persistent mist (best morning at Horseshoe Falls, afternoon at American Falls).
• Night: Colored LED illumination (tourism) — not natural.

Seasonal/Weather Variation

• High flow (spring melt) → more white, less green.
• Low flow (winter) → greener, clearer.
• Algal blooms rare (cold, turbulent).

The "color" is physics + geology + light—not pigment.