What environmental factor causes a gray patch next to a bright blue area to appear slightly reddish or yellowish?

Answer

Surround Color (Simultaneous contrast)

Simultaneous contrast occurs when the color of the background influences the perceived color of the foreground object, as the visual system tries to neutralize the strong adjacent input.

What environmental factor causes a gray patch next to a bright blue area to appear slightly reddish or yellowish?

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How do Humans Perceive Color? - YouTube

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