Step 1: Understanding the Concept
The question asks to identify a "warm" colour from the list. In colour theory, colours are often divided into warm and cool categories based on their psychological associations.
Step 2: Detailed Explanation
Warm colours are associated with warmth, such as sunlight and fire. They include reds, oranges, and yellows. They tend to feel energetic and advance in space.
Cool colours are associated with coolness, such as water, sky, and foliage. They include blues, greens, and violets. They tend to feel calm and recede in space.
Based on this classification, Red is a quintessential warm colour. Blue, Green, and Parrot Green are all cool colours.
Step 3: Final Answer
Therefore, Red is the warm colour among the options.