Each color represents a different stage of human life. Blue for birth. Purple is a sign of growth. Green for youth. Orange for the summer and autumn of life. White for age. Violet for darkness and death. Black for death.
The prince was trying to fight off death using colorful rooms, hoping
that sickness would not intrude on colors that reflect purity, peace,
life, or energy.
The main idea is more specific than a theme . The theme could be food and the main idea might be that people need to be more careful about what they eat . Hope that helped