Color constancy and retinex

Sun light image shot with camera color balance set for sunlight. The camera was set to manual and kept with this color balance setting. Papers is blue, green, red, yellow, and white.
Fluorescent lighting, the black is the table top on which the paper was placed:
Incandescent bulb, 100 watt soft white:
An incandescent black light, there is outdoor background light present in the classroom:
For the students, the papers did not change colors as much as they actually did as revealed by the camera. For the students, their brains rebalanced the images so that they perceived the colors as seen in the first image.

Lecture links:
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