The barn above looks red because certain rays of light are absorbed by the barn and other rays of light are reflected by the barn. What must be true about the original sunlight before it hits the barn?
The sunlight is perceived by our eyes as white because it is a mixture of seven colors - violet, indigo, blue, green, yellow, orange, and red.
When these colors of light separate from each other and are differentially absorbed and reflected, we can see the different objects in different colors.
The reason for the differential absorption and reflection is that the different colors have different wavelengths.
Therefore, the barn looks red because the red light is reflected by the barn and other lights are absorbed, however, the original color of the sunlight is white.
