the scale effect of colour
by Martyn de Young


An accomplished fine scale modeller once told me: “There is nothing that will spoil a model more than the judicious application of the correct colours.”

In this day of ever more accurate kits and models in all scales, and the lengths modellers go to achieve the perfect dimensions, the correct number of rivets, accurately profiled wheels,… this may seem like a strange comment, but a simple experiment into the Scale Colour Effect can prove the point. The scale colour effect is the visual phenomenon of distance effecting what the eye sees, and how the brain interprets the visual clues.

Any object viewed from a distance, say 50 metres, looks a different colour to that same object seen at two metres. This is because of the particles in the air between your eye and the object. These particles include dust, water, smoke, pollen. As objects get further away, this dulling of colours becomes more pronounced.

To test this theory:
• Cut out two squares of card, one 50 x 50 mm (two inches for the “traditionalists” among us!) and the other 300 x 300 mm. (about a foot square).
• Paint both squares matt black.
• Place the larger card against a light, neutral background.
• Holding the smaller card at arms length, walk backwards until both cards appear to be the same size.
• The colours of the card will no longer be the same. The closer card will be closer to the original colour and more vibrant; the distant card will appear a lighter, less distinct, grey.
• Try the same with pure white.

Every model, regardless of scale, needs appropriately scaled colour. A model – regardless of the degree of technical accuracy, is an attempt at creating an artistic illusion, and nothing destroys that effect quicker than poorly executed painting, or colours that are too bright. So having researched the exact colour of an L&B Manning Wardle underframe in 1898, how can this colour be accurately portrayed on an OO9 model?

The colour of a 1/76th scale model loco at one foot should appear the same colour and shade as a real loco 76 feet away.
A number of different formulae have been developed to produce a more accurate colour representation, but a simple and effective method is this:

A simple way to replicate this scale colour effect is to add to the original colour. In 1/76 scale adding about 15% matt white to the prototype colour seems to give gives a fair match. For smaller scales, more white is generally required to give the same effect. For 1/43 scale, around 5% is required. The exact proportions are largely a matter of personal taste, and a degree of experimentation is advised (also, bear in mind the variety of the prototypes, both in original colours and the degree of weathering each vehicle was subjected to over time).
The final effect should give at least a slightly "washed-out" or "faded" look when viewed up close.
Black and white should never been used alone - always mix at least a touch of green, brown, or other dark colour to black, and add a hint of any surrounding colours to white.

Once the colour looks right, another factor to take into account is gloss – a matt finish is generally preferred, as this scales down the glow from reflections (particularly noticeable in some photographs) which can make even the best models look like – well, models!

As well as to rolling stock, the scale colour effect can be used equally effectively on buildings and scenery, and can transform a layout or diorama. If a model is to be viewed mainly from one direction, applying gradually lighter colours to objects as they appear further back can help add apparent depth.

One further aspect to consider, and one that can make a tremendous difference, is the lighting under which the model will be viewed – careful addition of variations in colour can accentuate or obscure shadows and details to make an artificial light source appear more realistic.
Modeller, David Zelly, has experimented a great deal with lighting effects, (he is a professional stage lighting technician, so he ought to know).
In principle, he advocates that the lighting pelmet should always be at least 12" forward of the model so that the fronts of buildings are correctly lit. He uses daylight lighting in the foreground and a softer light towards the back, which gives a better feel of depth.  (see this article about County Gate)