To solve the problem, we need to identify which color is least deviated when white light passes through a glass prism.
1. Understanding Dispersion of Light:
When white light passes through a prism, it splits into its constituent colors due to **dispersion**. This happens because different colors (wavelengths) of light travel at different speeds in the glass, causing them to bend by different amounts.
2. Order of Deviation:
- Violet light has the shortest wavelength and is deviated the most.
- Red light has the longest wavelength and is deviated the least.
Final Answer:
The least deviated color is \({\text{red}} \).