All of these colours (except for the generic silver, rust and greys) are based on prototype photo samples, as well as paint chips when available. They are not "official" colours.

To sample the colours, I take a 16 x 16 pixel sample from 5 to 10 properly exposed photos showing clean, unfaded paint, and determine the combined average RGB values of all the samples. I then increase the saturation very slightly and adjust the luminosity (slightly lower for dark colours and slightly higher for lighter colours) to account for dust or glare. If I find a very good online paint sample, I give extra weight to the RGB values of that sample.

Below is an example of colour matching based on samples from eight photos, in this case for the CSXT YN2 paint scheme. The RGB values in brackets indicate the sample average, while the second set represents the final colour after adjusting saturation and luminosity.

colour matching

These colours are used only in the 1:18 drawings. Most of them are different from the ones I used in the 1:55 and 1:36 drawings, for which I matched the colours simply by eye.

In addition to changes caused by dirt or fading, some prototype colours varied significantly depending on the era and location the painting took place. I do not include these variations unless the colour change was intentional.