Mixer · Temperature · Contrast · Notan
Mix Two Colours
How coloured light combines — screens, stage lighting, projectors, coloured torchbeams. Mixing all colours approaches white.
How artist pigments mix — paints, inks, dyes, any physical media. Mixing all colours approaches dark brown-black.
Why they differ: Mixing light is additive — combining wavelengths approaches white. Mixing pigments is subtractive — each pigment absorbs wavelengths, so combinations grow darker and duller. Red and green light makes yellow; red and green paint makes a muddy olive-brown.
Where the difference is most visible: Yellow + blue is the most striking pair — as light they average to a neutral grey, as pigment they create green. Red + green gives yellow as light, but a muddy brown as pigment. Two colours that are already close on both wheels (like red + blue → purple) will produce very similar results from both models. The gap widens most on cross-wheel complementary pairs.
The RYB model (Red-Yellow-Blue) is the traditional artist's colour wheel — an approximation, not physically exact, but a reliable practical guide for mixing at the easel. Printing uses CMY (Cyan-Magenta-Yellow), which is mathematically more precise but less intuitive for painters.
Base Colour
Key Light Temperature
Suggested Highlight, Midtone & Shadow
The warm/cool rule: In warm key light (sunlight, tungsten), the shadowed side receives cool reflected sky — shadows shift toward blue-violet. In cool or overcast light, shadows receive warm bounce from the ground and environment — they shift toward orange and red.
Painting shadows as "just the colour darkened" looks flat and lifeless. Introducing the opposite temperature into shadows is one of the most reliable ways to make light feel real and forms feel three-dimensional. The values shown are a starting point — adjust to taste and reference.
Atmospheric perspective: Distant objects also take on the ambient light temperature (usually blue-cool). Foreground shadows can be warm; background darks shift cool regardless of local colour.
Your Colour
The identical colour circle appears on six different backgrounds below. Your eye adjusts to surrounding colour — watch how the same swatch reads differently in each context.
Josef Albers' observation: Colour has no fixed appearance — it only exists as a relationship. The same neutral grey looks lighter on black and darker on white. The same orange looks more saturated against its complement (blue) and duller against a warm neighbour.
For painters, this matters practically: the colour you squeeze from a tube is never the colour you see on canvas, because the canvas is always surrounded by other paint. When a colour "looks wrong," the problem is usually the neighbouring colours, not the paint itself. Train the eye to see colour as relationship, not absolute value.
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What is notan? Notan (濃淡) is a Japanese design concept meaning "dark-light" — the balance of light and dark shapes as a composition. Before committing to colour, many painters work out their image in 2–3 values to ensure the structure holds on its own terms.
A strong 2-value notan means the composition reads clearly in pure black and white. If the image fails at 2 values, colour will not rescue it. Use this on your own reference photos or concept work to study value structure, identify weak areas, and simplify complex scenes before painting. The 4-value version maps to the classic zone system: shadow, low-mid, high-mid, and light.
The Colour Mixer shows how the same two colours combine differently as light (RGB additive) versus pigment (RYB subtractive). Understanding this difference is essential for anyone working across both digital and traditional media — why red and green light yields yellow while red and green paint yields a muddy brown.
The Temperature and Light section applies the warm/cool principle directly: choose an object colour and a key light temperature, and see suggested highlight, midtone and shadow colours with the correct temperature relationships. Knowing that warm sunlight produces cool shadows — and vice versa — is one of the fastest ways to make painted lighting feel convincing.
The Simultaneous Contrast demo demonstrates Josef Albers' central observation from Interaction of Colour: no colour exists in isolation. Every colour is modified by its surroundings. Training the eye to see colour relationships rather than absolute values is a core skill for any painter or colourist.
The Notan / Value Study tool strips any dropped image to 2, 3 or 4 values, letting you evaluate composition purely on the basis of value structure. All processing is done locally in the browser — no image leaves your device. Built at Impheim as a free resource for the art community. More free tools in the Impheim Tool Workshop.