Which colour would be more useful in a snowy Himalayan scene?

Correct answer: Light blue

The relevant artistic principle is that cool colours can communicate coldness, distance, and a quiet atmosphere. Light blue is therefore especially useful for suggesting snow, icy air, distant mountains, and reflected sky in a Himalayan scene. Option D is correct. Red, orange, and yellow are warm colours; they may be added as small accents or sunlight, but they do not create the main cold, snowy impression as effectively as light blue.