Which of the following statements is correct regarding the propagation of light of different colours of white light in air?

Options

A. Red light moves fastest
B. Blue light moves faster than green light
C. All the colours of the white light move with the same speed
D. Yellow light moves with the mean speed as that of the red and the violet light

Explanation

To determine which statement is correct regarding the propagation of light of different colors of white light in air, we can analyze the behavior of light in this medium.

### Step-by-Step Solution:

1. **Understanding White Light**: White light is composed of multiple colors, which can be seen in a spectrum (red, orange, yellow, green, blue, indigo, violet).

2. **Propagation in Air**: When light travels through air, it is important to note that all colors of light travel at the same speed. This is because air is a uniform medium for light propagation.

3. **Speed of Light Colors**: If different colors of light traveled at different speeds, we would see them arrive at different times. For instance, if red light were the fastest, it would reach us first, followed by other colors. However, this is not observed in air.

4. **Observation of White Light**: Since all colors of light travel at the same speed in air, they reach our eyes simultaneously, allowing us to perceive white light rather than seeing individual colors separately.

5. **Conclusion**: Therefore, the correct statement regarding the propagation of light of different colors of white light in air is that all colors travel at the same speed.

### Answer:
All colors of white light travel at the same speed in air.