This time we are looking at warm and cool colours. These are terms that are often used by interior designers to describe the 'feel' of the colours in a room. They also have some really important qualities that you might want to consider when you are creating.
If you look at the colour wheel again, and draw a line through the centre that runs between yellow-green and yellow through the middle to between violet and red-violet, you have divided the colour wheel into two. The left hand side, or the colours with a strong blue base are known as cool colours, whereas the colours on the right or those with a strong yellow or red base are the warm colours.
As the name suggests in each case, the cool colours evoke a feeling of coolness or even coldness and warm colours convey heat. As such if you are wanting to convey the feeling of the cool shadows of a forest, you would use greens and blues. Conversely, if you want to convey a hot summer's day, you would need to use warm colours.
As an example, consider the following images. They are both paintings of similar subject matter - a woman in an interior. The first, depicted in oranges, reds and yellows convey a pleasant feeling of warmth and cosiness. The second, of a lady engaged in cooking, conveys a feeling of hospital grade cleanliness, due to its inclusion of cold blues and despite the image content.
Source: Martin, J, (2002), Drawing with Colour, London: Quantum Books, p. 47 & 101.
It is important to note other inherent characteristics of warm and cool colours. Warm colours visually advance, or seem to come forward. This means that painting a room in warm colours will make it seem slightly smaller as well as cosy, whereas painting a room in cool colours will generally make it seem larger. Further, warm colours tend to be more prominent in a composition. Consequently, cool colours make better colours to use in a background, as they will tend to visually recede.
It is also worth remembering that a colour, whether it is warm or cool, can be made warmer or cooler, and in fact colours of paint often come in warm or cool options. An example of a cool red is alizarin crimson (because it tends towards the blue part of the spectrum) whereas a warm red is vermillion (which tends towards orange). Relatively, though, both are warm colours. You can add warmth to any colour by adding red or yellow, or you can cool down a colour by adding some blue.
Experiment with warm and cool colours to create the effects you are looking for in your paintings and spaces.