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

There’s a ton of literature and webpages about colourschemes, and both you and I have better things to do than studying all of them. In the following, therefore, I’ll try to assemble a simple, logical theory of colourschemes that doesn’t take an entire book to explain.

First premise:
There are basically four parameters you can adjust when it comes to colourschemes:

• Contrast: How complementary are the colours?
• Balance: How much are there of each colour compared to the others?
• Position: How are the colours positioned?
• Colour saturation/hue/shading: Strengthening, weakening or altering the individual colours.

Listed in order of importance: for instance, use of the last parameter when building with Lego is severely limited by the available palette)

Second premise:
Depending on how you vary the parameters, the colourscheme will vary between static/dynamic and boring/confusing: The goal is to hit the golden mean where everything is just right (I just recycled a part of my design theory for this one).

First parameter: Contrast (complementary colours)
Theory: Harmonious colourschemes are based on a kind of idealized colouring that; for instance, make flower paintings prettier than the real thing. According to Goethe & co this is because the brain wish to compensate or balance out dominating colours:

If you look at something red, the brain wants green (complementary or opposite colours on the colour-wheel), if you look at heavily saturated red, it wants lighter tones also (opposite saturation), and if the colour is shaded with grey or black, the brain wish to balance this as well.

Returning to the second premise, we don’t want to make things too pretty because it’ll end up too boring, on the other hand, we don’t want it too provoking either, cause at the other end of the scale the colourscheme just collapses into a complete mess.

Since it’s really easy to screw things up, so your best bet is probably to aim at “harmonious with a little twist” – or at least start out from there.

Practice: Somewhat similar to your colour television, the contrast button basically goes from weak greyscale to strong pairs of complementary colours:

Dual complementary colourscheme: Starting at the strong end of the contrast-scale, the dual complementary colourscheme is probably as harsh as it gets, especially if the colours are placed right next to each other.

Tetrad colourschemes: Made out of two pairs of complementary colours with equal distance on the colour-wheel. These colourschemes should combine prettiness (because they contain all the primary colours) with double complementarity. With a twelve-colour colour-wheel, you’ll unfortunately end up with one primary, one secondary and two of the extremely rare tertiary colours.

Split complementary colourshemes: Basically the same as duals, only you’ve split one of the colours into the two neighbouring colours on the colour-wheel in order to water down the contrast.

Triad colourschemes: Made out of three colours with equal distance on the colour-wheel. Pretty because they, like tetrad schemes, contain all of the primary colours, but less contrasting because none of them are directly complementary.

Non-complementary colourschemes: Naturally, colourschemes doesn’t have to be based on complementary pairs of colour. If they’re placed more than 60 degrees from each other on the colour-wheel you might achieve an elegant semi-complementary scheme, because primary and secondary colours from opposite sides of the wheel will be contained within the colours chosen. The same goes for earth tones, as these are based on all three primary colours.
If the colours are placed less than 60 degrees from each other, you could argue that we’re really talking about analogous colourschemes instead:

Analogous colourschemes: Are based on colours sitting close to each other on the colour-wheel such as yellow green, yellow, yellow orange and orange. While this kind of scheme will create pleasing variations in what would usually be one colour + greyscale, they lack the true dynamism of a complementary colourscheme.

One colour + greyscale: One step above plain greyscale, a single colour can add a splash of life that these colourschemes usually lack:

Greyscale colourschemes: With greyscale you can still get a heavy light-dark contrast, however, without the liveliness of colours, most of these schemes end up being either dull greyish or confusing zebra-schemes that are particularly difficult to photograph.

Ok, I haven’t had time to write or photograph more, so instead of dragging things out for several weeks and hit you over the head with a huge(r) blogpost, I’ll cut it off here.
In the following blogposts I plan to continue with the other parameters (balance, positioning, and saturation/hue/shading), followed by a small series of posts with examples of spacemocs announced on CSF (hopefully Jainsguide/CSF moc announcements are back up soon).