As promised, I’ll post the pertinent slides from the Chicagoland 2019 clinic here. This first post is the Colour Theory chapter. Check back for more chapters.
Colour Theory Basics:
Remember the Kindergarten colour wheel? Understanding the basics of how primary colours (red, yellow, and blue) are combined to create secondary colours (purple, orange,green), and how further mixing creates an infinite range of colours.
A colour’s lightness and darkness is described by the words shade and tint. Tones are created by adding grey to a colour.
Colour temperature is way of understanding and categorizing colours.
Renaissance painters used paints created from pigments that came from clays found in various parts of Italy. These colours were essential to their work, and they certainly help our efforts to create realistic weathering effects. Umber is a colour from the Umbria region in northern Italy. Burnt Umber is a more reddened rendition, which is created by burning the clay in a kiln. Sienna is originally from the Tuscany region of Italy. This clay contains much iron oxide, hence its more red appearance. Burnt Sienna is, likewise, Sienna pigment that has been burnt in a kiln. Yellow Ochre was originally mined in Provence, and different renditions of Ochre which have more red in them were found elsewhere.
In the image below, I’ve photographed crude paint swatches, showing the colours of the earth on the left. I’ve added a swatch of a Oxide Patina by Abteilung because it’s a nicely formulated weathering colour.
It’s supremely convenient to just buy a bottle of paint that claims to be your favourite railroad’s colour, and load your airbrush. Knowing how to mix your own colours will free you from the reliance on railroad-named colours of hobby paints, but even if you never actually make your own colours, you can modify colours to suit what your eye sees. A basic understanding of colour theory will help you choose weathering colours and filters to shift the colour of your model.
When it comes time to fade or weather a piece of rolling stock, remember the basic colour wheel. Use white or yellow to lighten a colour. Use blue or brown to darken.
And, finally, a word about grey. Hobby paints that are labelled as grey are typically based on blues and greens. If you want to create a tone, use a neutral grey, which is any combination of black and white only (no colours).