Friday, September 6, 2013

Understanding Colour

When white light, coming from the sun or another light source, strikes an object it is then reflected back to our eyes by that object. Different surfaces absorb, reflect and mix light differently due to their structures and this is why we see different colours. So in painting, different pigments on the surface of the canvas are able to do the same. There are 3 different properties in colour:
1. Hue: or the colour itself eg. Blue, red, yellow
2. Value: or else the darkness or lightness of colour and this is what creates contrasts
3. Intensity or tone: pure colour comes from the tube but it is rarely used as pure and so it has to be mixed. 
 

Hue

The above picture shows the colour wheel. There are 3 primary colours from which all the other colours can be mixed.....Yellow, red, blue.
Secondary colours are those mixed from two of the primaries eg: blue + yellow = green
Tertiary colours are those mixed from a secondary and a primary eg: orange + yellow
Colours are said to be either warm or cool. Red is warm while blue is cool.
However there are warm blues (eg: ultramarine blue) and cool blues such as cerulean, cobalt and phtalo blue. There are also warm reds such as the cadmiums and cool reds (alizarin red).
The earth colours such as raw sienna, raw umber, burnt sienna and burnt umber are located at the inner part of the wheel towards the orange side.
Using cool colours for early morning scenes as well as for winter scenes while warm colours are used for afternoon or summer/Autumn scenes.
Appropriate use of warm and cool colours in a painting will give you depth and perspective, that is using blues for distant objects such as distant mountains and warm colours for foreground objects.

Value

The darkness and lightness of colour will give contrast and hence also useful for perspective. White is the lightest colours while black is the darkest...however black is rarely used in a painting as it is too strong (use Payne's grey instead). The addition of white to a colour will create a tint. Always keep an abundant amout of white available to use. Colours are usually darkened with a grey to create a tone. The addition of white or greys will affect the intensity of the colour. Adding black will create shade.

Suggestions applicable for oil painting

Always use artist quality oil paints (these contain more pigment and so do not fade when mixing). Also it will be easier to create texture when using knife for painting. You cannot work well with runny colours.
If oil colours are too thick then thin them with gum turpentine or linseed oil, only to a creamy consistency. The more oil you add the more time it takes for the painting to dry. Gum turpentine is usually added to colours used for the underpainting for fast drying.
Add more oil to the top layers of a painting as these has to dry the last., this is known as FAT over LEAN. If upper layers dry before the lower ones then this can cause cracking. Always paint in adequate ventilation as oil colours are toxic even if they do not smell. When starting painting, start from very dark (usually monochrome) underpainting, just indicating the basic shapes and structures and light/dark areas. Always keep in mind that there is no light if there is no dark and so you have to create contrast by putting highlights over darker areas. I will give more details how to use colours when discussing landscape painting.

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