What do You Mean by the Word ‘VALUE’ When Talking About Colour?
‘Value’ means the lightness or darkness of a colour. The value of a colour can be most readily determined by making a comparison to a scale of neutrals graded from black to white. Value scales may be numbered with as many graduations as necessary with black usually are represented as “o”. 
Dark colours are considered low in value while light colours are higher in value.
The human eye can easily perceive about five degrees of value beginning with black and ending with white. We can increase the value of a colour (or lighten it) by mixing it with white; we call this new hue a ‘tint’. We can also increase the value of a colour with the addition of a lighter colour, such as yellow.
Darkening or lowering the value of a colour is achieved through the addition of black. The new hue is called a ‘shade’. The addition of a darker hue, such as blue, also lowers the value.
There are 4 Tonal groups where VALUE is an important factor in choosing the right colours.
12 Tone Light Summer – 12 Tone Light Spring – 12 Tone Dark Autumn – 12 Tone Dark Winter
How do check to see if the value of a colour is correct for you? Hold your colour sample (found in your 12 Tone Personal Book of Colour) next to the test colour; in day light of course. Squint your eyes as if you are looking into the sun. When you squint your eyes the colours seems to disappear leaving just the value. When the colour of your sample and the test colour match in lightness or darkness you have found the true value of your test colour.
Try this experiment on the value scale above . Notice the yellow is consistent in value at the light (top) end of the scale, and the blue/violet is consistent at the low (bottom) end.
Why is Consistency in Value Important for Colour Harmony?
Look at the picture on the right. The colours in this flower are consistent in their high value (light, pastel colours).
Dark colours do not belong here, their inclusion would destroy the natural colour harmony of the flower.
Similarly, this inconsistency in value is the reason why people, who’s colouring is dominated by high value, have such a difficult time looking slim, young, healthy and blemish free in low value, or dark colours.
So Where Does Black Fit in?
People whose colouring is dominated by low value, or depth of colour, naturally look better in black. Why? Because the value of black is consistent with their predominant colour dimension which is darkness; resulting in natural colour harmony.