Ok, we all want to make better colourschemes, and use more of our collections, but once you’ve decided on some particular colours, how much of each should you use? In this second part of the colour-investigation, we’ll take a look at colour balance:

Quantity contrast
It shouldn’t come as a surprise to anyone, that different colours have different brightness (ie. if you turn a colour photograph into black and white, the colours will be converted to different shades of grey).
Back in the 19th century Goethe came to the same realization and attached the following brightness values to primary and secondary colours: 

Brightness values are used to calculate how much you need of two contrasting colours in order to balance them:
Yellow-purple = 9:3 =3:1
Orange-blue = 8:4 = 2:1
Red-green = 6:6 = 1:1

• This means that in a dual contrasting colourscheme you’ll have to use
  Three times as much purple to balance out yellow,
• Twice as much blue to balance out orange, while
• Equal amounts of red and green would be balanced.

It would probably be possible to reach more precise numbers for the different lego colours by testing the official RGB/CMYK-values in photoshop, but for the purpose of designing lego colourschemes that would probably be overkill.
To illustrate these numbers, Goethe also made special colour-wheel with proportionate amounts of the 6 primary and secondary colours, which I’ve tried to recreate in lego above.

Colour mixing
Another interesting aspect of the colour theory as explained by Edwards (2004), is how you mix colours:

• Black: Equal amounts of the primary colours (red, blue and yellow) create a very pretty black.
• Accent/highlight: colours can be shaded or tinted by adding a tiny amount of its complementary colour: this should result in a pretty or vibrant shading/lighting of the colour.
• Muddy colours: If you mix larger but unequal amounts of all the primary colours the result is usually some dirty looking version of brown.

If we tentatively consider a the various colours in a moc as a single, mixed colour, it might be possible to explain why some colourschemes work better than others, and possibly show the way towards some unusual combinations:

Rainbow warriors are usually frowned upon among serious lego hobbyists, but bright colours need not be such a bad thing: All bright colours are based on one or more of the primary colours (yellow, red and blue), so if these three colours are represented in equal amounts in the colourscheme, it might actually work under the heading of “pretty black”.
However, if large quantities have been used in unbalanced proportions, for instance if two of the primary colours are heavily represented compared to the third (in the moc as a whole or in particular sections), the colourscheme might be compared to the “muddy” colour mix.
Generally speaking, though, good colour grouping will counter this effect, because colour mixing will at least be reduced at the local level (more about this next time).

The ‘three colour rule’ is often handed down to less experienced builders to improve their building – with a glint in the eye, because although it definitely work, there aren’t really any rules when it comes to lego.
However, viewing a colourscheme as a single colour created from the three primary colours might support this ‘rule’:
As an example we can pick a subtle and inoffensive colourscheme based on equal amounts of blue, green and orange:
At first glance, there isn’t any contrasting colours, because all of them are situated in the same side of the colour-wheel, which result in a subtle analogous colourscheme.
However, if we break down the colours in their primary component we get something like this:

(Blue) + (green) + (orange) =
(Blue + blue) + (blue + yellow) + (yellow + red) =
3 blue + 2 yellow + 1 red

Not only does this mean that the colourscheme contain a pair of contrasting colours (red and green), it also adhere to the ‘three colour rule’ by having three colours in decreasing amounts (“primary”, “secondary”, and “accent colour”).

This sort of ‘internal contast’ might also explain the huge popularity of the “new” earth-toned colours in the lego palette (dark red, -blue, -green, -grey, tan etc.):

As it can be seen from the CMYK-values, the brownish shades of these colours is created by mixing in all the primary colours as well as white or black, and they will therefore match any colour or greyscale you’d care to throw at them.
By containing all the primary colours in unequal amounts, they furthermore arrive with the ‘three colour rule’ already build in, with the result that colourschemes primarily based on greyscales and any one of these colours rarely fail.

Next time we’ll take a look at the third parameter: Colour positioning.

* Betty Edwards 2004: Color - A course in mastering the art of mixing colors