In painting, a 'warm' colour palette consists of:

In colour theory, colours are divided into warm and cool groups based on the psychological and visual sensations they produce. Warm colours are those associated with heat, fire, and sunlight. They advance visually, meaning they appear to come towards the viewer, and they evoke energy, passion, and warmth.

The warm colour group consists of yellow, orange, and red. These colours sit adjacent to one another on the colour wheel and share a common association with warmth. Red is the colour of fire, orange the colour of flames and autumn, and yellow the colour of sunlight.

By contrast, blue, green, and violet are classified as cool colours because they are associated with water, sky, and shade. White, grey, and black are neutral (achromatic) colours, not warm. Brown, navy, and silver are a mixture of neutrals and cool tones.

When revising colour theory, remember that the warm-cool division follows the colour wheel: one half (red through yellow) is warm, the other half (green through violet) is cool.