Colour is emotive. The British and Americans can’t even agree about how it’s spelt. Colour is also complicated. Colour provokes clear and strongly held opinions – which are generally “wrong”. In this case, “wrong” means over-simplified. If it’s easy to get “wrapped around the axle” about colour, is it also possible to keep it simple and yet be true to the original. Are there tools which both well grounded and, above all, useful to us as model makers? Read on.
The Problem with Colour
Colours are given descriptive names – light brown, olive drab, NATO Green and the classic: Dunkelgelb. There are two problems with this:
- The name might not cover all the variations. There were at least four official colours of Dunkelgelb and many more variations in the field after mixing and weathering.
- We all perceive colour differently. Our eyes and brains affect our perceptions, as do transmission devices such as photos, monitors, film etc. So trying to compare colours on a tablet or monitor is delusional, you’re not looking at the colour itself but a representation of it using a very limited palette.
-This leaves us with three choices:
- Don’t care – it’s only a model and if it looks about right, that’s good enough.
- Rely on someone else – if a supplier says it’s a “Real Colour”, that’s good enough. So called authentic paints vary a lot, some are close to the originals but others are way off. How can you reliably tell the difference, assuming you care about accuracy?
- Do it yourself, objectively. We need a reliable and accurate way of comparing colours and altering them. Read on:
How Colour Works
Colour is light, interpreted by our brains. Like any other waveform, light waves vary in frequency, amplitude and wavelength but enough of physics. We’re used to terms such as colours, tones, tints, shades. Those words are attempts to describe how a colour may vary. The problem is that you can’t measure them. Although an artist may not use the same terms as a photographer, there is a general agreement that colour has three qualities. Have a look at this picture:
If you take a red and add black or white, you make the paint look lighter or darker. These variations are commonly described as tints and shades but a better term for us is Brightness. Photographic editing software would call it Luminance but Brightness is easier to grasp.
Take the same red and add yellow you move the “colour” towards orange. These variations are changing the Hue or Chrominance (from the Greek Chroma – colour).
Finally, add grey to the red and the hue becomes less vibrant, less intense. This is changing the Saturation.
So we now have a language with which to describe and measure colour:
- Hue: where is it on the colour spectrum?
- Brightness: how light or dark?
- Saturation: how pure and intense is the colour?
There is a very simple and clear explanation of Hue, Brightness and Saturation here:
Incidentally, you can explain how a model filter works using these terms. Mix enough colours together and you’ll eventually get grey ie totally desaturated colour. Filters desaturate a basecoat to dull it and blend different colours. Use it on camouflage and the colours become more unified and less stark. A filter can also change a hue or darken/lighten a hue.
We'll avoid the whole subject of primary, complementary and secondary colours because it’s a minefield and not terribly useful to us. We really only need to know something about whether one “colour” matches another (is this model paint an accurate representation of the original) and how we alter paint (how do we make it lighter, less intense, vary the hue). This incidentally is one very strong reason for using oils for weathering. Since they are infinitely mixable and translucent, with oils you can easily vary hue, brightness and saturation, which is not easy with acrylics or enamels.
What was the Original Colour?
If you want an accurately coloured model, you have to know what colour the original was. This is a huge subject which has kept anoraks busy for years. Fortunately, military authorities tend to be very strict about paint specifications. They use international colour matching standards to specify paint qualities in order that paint suppliers produce consistent and reliable products. This incidentally is one of the pitfalls of German WW2 colours, because as the war progressed, paints were increasingly unreliable and variable in application after being mixed by diluting a paste.
There are three standards relevant to us:
- RAL. RAL stands for Reichs-Ausschuß für Lieferbedingungen. Set up in 1927, the RAL maintains the German standard colour system. Colours are described using a four digit code, eg RAL 7028 Dunkelgelb. You need to know though that the colour charts we see today are a post war system, which eliminated some of the wartime colours. The wartime standard was RAL 840R. For that reason, RAL has to be used with care.
- BS381c. The British Standards Institute system is pretty universal and was used to specify WW2 military colours. The WW2 standard was BS987 but most of the colours have equivalents in the modern standard chart, BS381c. There are many conversion charts available online.
- FS595. The US Federal Standard 595 has its origins in the problems the US government had in obtaining consistent colors for military equipment.
How do I compare the original colour with a modern paint?
These standards provide colour charts which describe a catalogue of individual colours. To compare colours you need a tool which describes the whole continuous colour spectrum, known as a colour space. This is inevitably another minefield. There are colour spaces for print, for digital use and very sophisticated systems which take into account hue, brightness and saturation and mimic the colour receptors in the human eye. An example colour space is here:
Again, enough science.
All we need to know is that these systems ascribe three values to describe a specific colour and one of them, CIE 1931, takes into account luminance and chrominance.
Other systems in common use such as sRGB (optimised for digital use), CMYK (for print use) and Munsell also use a set of three values which describe a mix of the primary colours, whether those are red, green and blue or cyano, magenta, yellow and black.
There’s no real need to understand what the three values mean because we’re only going to use them for comparison. We first need some tools to help us. This is where I need to introduce a really useful online resource:
https://www.e-paint.co.uk
This website has all the common colour standards and gives descriptive values for each colour in all the main colour notations. Once you’ve got a description of the original colour, you have a means of comparing it with modern paints.
Take NATO Green for example, one of the colours used on Chieftain camouflage. NATO Green is a BS381c colour:
E-paint will then give you useful information about colour values, which you can use in other programs to compare colours and, in another page, conversions to other colour standards:
I’ve highlighted the values in CIE L* a* b* and sRGB. E-paint also gives close matches in other colour standards. This is useful because model paint manufacturers use different standards. Vallejo for example quotes FS595 values for their paints and mixes to achieve historic colours. See their useful conversion chart here:
https://acrylicosvallejo.com/wp-content ... colors.pdf
Now for the punch line: someone has done all the hard work for us. There are two apps which allow us to:
- Compare original colours with modern model paints
- Make up accurate colour mixes if a model paint isn’t available
- Specify original colours in a language which commercial paint mixers can use
iModelKit:
iColorKit:
I won’t go into using the two apps because they’re self-explanatory but here are a couple of examples of use:
Example One – how do I paint a Chieftain in Berlin Armoured Squadron Urban Camouflage?
- What were the original official colours? Using Dick Taylor’s Warpaint, Volume 3, we establish that the original colours were White, Dark Admiralty Grey (to BS381C 632) and Service Brown (to BS381C 499)
- Who makes an accurate Dark Admiralty Grey? Using iModelKit, we can find a match. We select the BS381c colour palette from the paints menu and get a chart of possible matches:
We can see that Tamiya XF77 is a match, as is Vallejo 70.992. To check this, we can tap on the calculator icons to give us a direct measure of how good the match is, using the CIE notation. (Any figure Delta figure under 10 is a close match, any under 1 is undistinguishable to the naked eye).
We can see that Tamiya XF77 is an excellent match. The Vallejo colour is close and you could use the iModelKit paint mixer to work out an exact match. Let’s do that with the third Berlin colour, Service Brown.
Service Brown is BS381c 499. We select this in the top section (Choose Reference). We then tap on + New Paint. The app asks us to choose a paint type. Sticking with Tamiya, we get a list of colours, in descending order of match. Against each is a measure of how close the match is, in CIE notation. We add XF84:
We see that the overall match has a delta of 8.46 and that we particularly need more green (delta of -20). Tap on + new paint and select the top paint, Tamiya XF54 and now the match is closer, delta 5.87 but now we have too much blue (+9).
Three colours is about the maximum you would want for a mix but by adding XF72 we get a delta of 3.82, which is close. Note the arrows on the side.
These allow you to vary the proportions of paint, which up to now have been equal measures. It’s worth playing around with these. Better still, press the calculator icon and the app will select the best match for you. In this case, if we now double the proportion of XF54, we get an almost perfect match. Result. The final mix is two parts XF54 to one part each of XF84 and XF72.We might have found that there are easier mixes using a different manufacturer’s products but this example shows the power of this tool.
Example Two - Is AK753 an accurate match for Dunkelgelb (Initial)?
I’ve cautioned about the inaccuracies of digital representations but there is one tool in both apps which, if used with caution, can be useful. It’s the colour picker, linked to your tablet or phone camera. The apps will allow you to use a photo of a colour chip to establish the colour notation for that colour. If, for example, you have an authoritative colour chip, this can be a way of checking the accuracy of a so called authentic model colour, using the colour comparison tool in iColorKit. You could use the colour picker photo tool to compare an authentic chip with a sample of model paint. You have to be careful to avoid artificial light and photograph both colours in the same light.
AK-Interactive offer a range of colours based on originals. We can compare AK753 Dunkelgelb (Initial) with the equivalent colour chip presented by the widely respected source Tomas Chory.
From iModelKit, we establish a description of AK753 in CIE notation.
We then use the colour picker camera in the Compare Tool in iColorKit:
Entering the two values into the compare tool, we get a not unsurprising result, which is that the colours are not a good match:
Of course, we could then use the colour mix tool in iModelKit to refine the colour but a better option might be to find an alternative model paint. This method has to be used with caution but can be a useful check.
So does any of this matter? Some modellers don’t much care about accuracy of colours and for others, there is a ready made let out which is that colours of AFVs on operations are affected by so many other factors that spending a lot of effort to get an historically accurate basecoat is seen as a waste of time. For others, it’s worth putting in some effort to create an authentic replica of the real thing, the essence of scale modelling.
As I said at the beginning, colour is a minefield of complex physics, passionately held prejudices and impenetrable and contradictory terminology. If this guide has offered any tools which are actually useful, it will be worthwhile.
