The colors of the color wheel can be divided into two categories according to the atmosphere and emotions they provoke. Vivid hues that bring about a sense of warmth are labeled warm colors. This includes hues from red-violet to yellow.
Hues that generate the exact opposite feeling are called cool colors. They are more passive than warm colors and tend to be associated with cool temperatures and relaxation. All hues from yellow-green to indigo are considered cool colors.