Question

Explain why a blue object appears black when viewed through a red glass sheet.

Answer 1

Color addition and color subtraction:

1. Color addition: When we combine two primary colors, the color obtained is called a secondary color. This method is known as color addition.
2. Color subtraction: The method to produce color by removing colors from the white light is called color subtraction.
   

The appearance of the color of an object:

1. Different colors of the objects are the result of the reflection and absorption of some or every color.
2. When white light shines on a blue object, it reflects blue light while absorbing the red and green lights.
3. When the blue object is viewed through a red glass sheet, the red light falling on the blue object will be absorbed and nothing gets reflected.
4. So the blue object would appear dark almost black when viewed through a red glass sheet.