In traditional colour theory (paint and pigment), the primary colours are red, yellow, and blue — they cannot be mixed from any other colours. In digital screens (RGB), the primaries are red, green, and blue. In modern printing (CMY/CMYK), they are cyan, magenta, and yellow.

Secondary colours are made by mixing two primary colours in equal parts. In traditional theory those are orange (red + yellow), green (yellow + blue), and purple (blue + red).

Tertiary colours are made by mixing a primary with an adjacent secondary, producing six in-between hues: red-orange, yellow-orange, yellow-green, blue-green, blue-violet, and red-violet.

RGB (red, green, blue) is an additive model used for screens — colours are produced by adding light. CMYK (cyan, magenta, yellow, key/black) is a subtractive model used for printing — colours are produced by absorbing light from white paper through ink.

A hex code is a six-digit code prefixed with # that represents a colour in RGB. Each pair of digits (00–FF) gives the intensity of red, green, and blue. For example, #FF0000 is pure red, #00FF00 pure green, #0000FF pure blue.

Hue is the colour itself (red, blue, green). Saturation is how vivid or muted it is — high saturation looks pure, low saturation looks grey. Lightness (or brightness) is how light or dark the colour appears.

Red and blue mixed together make purple. Adding more red shifts it toward magenta or wine; adding more blue shifts it toward violet or indigo.

Blue and yellow mixed together make green. More yellow gives a warmer, lighter green; more blue gives cooler teal-greens.

Red and yellow mixed together make orange. More red produces a deep red-orange; more yellow gives a brighter, lighter orange.

Brown can be made by mixing all three primaries (red + yellow + blue) in unequal parts, by mixing complementary colours like orange and blue, or by adding a touch of black to orange or red.

The colour wheel is a circular diagram showing the relationships between primary, secondary, and tertiary colours. It is the most common tool for finding harmonious colour combinations.

Complementary colours sit directly opposite each other on the colour wheel — like red and green, blue and orange, or yellow and purple. Paired together they produce the highest visual contrast.

Analogous colours sit next to each other on the colour wheel (such as blue, blue-green, and green). They look harmonious and easy on the eye, which is why they are common in nature.

Triadic colours are three colours evenly spaced around the colour wheel (such as red, yellow, and blue, or orange, green, and violet). They create vibrant, balanced palettes.

Warm colours — reds, oranges, yellows, and warm browns — evoke heat, energy, and the sun. Cool colours — blues, greens, and purples — evoke water, sky, and calm. Warm colours appear to come forward in a composition; cool colours appear to recede.

Red commonly symbolises passion, love, anger, danger, and energy. In China and India it represents luck and prosperity; in much of the West it can also mean stop, warning, or alert.

Blue is associated with calm, trust, stability, and (idiomatically) sadness. It is the world's most popular favourite colour and is heavily used by banks, tech companies, and healthcare brands for its trustworthy feel.

Green represents nature, growth, health, freshness, and renewal — and money and envy in some Western contexts. It is considered the most restful colour for the human eye to look at.

Yellow symbolises happiness, optimism, sunshine, and energy — but also caution (as in road signs) and, in some idioms, cowardice. It is the most visible colour in daylight, which is why school buses and warning signs use it.

Black is associated with sophistication, elegance, formality, and power, but also with mourning, the unknown, and evil. It is what we see when no visible light reaches the eye.

In most Western cultures white symbolises purity, cleanliness, peace, and innocence (white weddings, white doves). In many East Asian and South Asian traditions, white represents mourning and is worn at funerals.

Purple is associated with royalty, luxury, mystery, and spirituality. The dye was historically extracted from sea snails at huge expense, so only emperors, kings, and senior bishops could afford it — that link to power survives today.

Pink represents love, kindness, tenderness, and femininity in modern Western culture. Lighter pinks suggest sweetness and innocence; hot pinks convey playfulness and confidence. Its strong gender association is largely a 20th-century invention.

Orange combines red's energy with yellow's cheer, so it symbolises enthusiasm, creativity, warmth, and adventure. It is also strongly tied to autumn, harvest, and Halloween.

Colour blindness is a condition in which certain colours are difficult to tell apart, most commonly red and green. It affects roughly 8% of men and 0.5% of women, is usually inherited, and is rarely a complete absence of colour vision.

Green is the rarest natural eye colour, found in roughly 2% of people worldwide. Grey, amber, and violet (very pale blue) are also uncommon. Brown is the most common, occurring in over half the global population.

Surveys done across many countries consistently put blue as the world's favourite colour — chosen by roughly 30 to 40% of respondents. Red and green typically come second and third; yellow is usually the least popular.

Classic clashes include two highly saturated complements at full strength (bright red with bright green), or close-but-not-matching tones of the same colour. Modern fashion breaks every "rule" deliberately, so these are guidelines rather than laws.

The sun is white. It emits all visible wavelengths roughly equally, which the eye perceives as white when seen from space. From Earth it looks yellow, orange, or red because the atmosphere scatters more of the blue light away before it reaches us.

Air molecules scatter shorter blue wavelengths of sunlight much more strongly than longer red wavelengths, so blue light bounces around the sky and reaches our eyes from every direction. This phenomenon is called Rayleigh scattering.

Plants contain chlorophyll, a pigment that absorbs red and blue wavelengths of sunlight for photosynthesis but reflects green wavelengths. The reflected green light is what reaches our eyes.

A tint is a colour mixed with white (lighter, softer). A shade is a colour mixed with black (darker, deeper). A tone is a colour mixed with grey (more muted, less saturated). All three are technical terms even though "shade" is often used loosely.

A monochromatic scheme uses a single hue with variations in lightness and saturation only — for example navy, royal blue, sky blue, and powder blue. It produces a calm, cohesive look common in minimalist design.

Hue is the pure colour itself — red, green, blue — without any added white, black, or grey. "Colour" is broader and includes the hue plus its lightness and saturation, so navy and sky-blue are different colours but the same hue.

The average human eye can distinguish around one million colours. People with a rare genetic condition called tetrachromacy may perceive up to a hundred million; people with colour blindness see far fewer.

Pantone is a proprietary colour-matching system widely used in printing, fashion, and product design. Each Pantone colour has a unique number that ensures the exact same shade can be reproduced consistently across paper, fabric, plastic, and ink.

HSL stands for Hue, Saturation, and Lightness — a colour model that is often more intuitive for humans than RGB because it separates the colour itself (hue) from its vividness (saturation) and brightness (lightness).

HSV (Hue, Saturation, Value), also called HSB (Brightness), is similar to HSL but defines lightness differently — pure colours sit at maximum value rather than the middle. It is widely used in digital art software like Photoshop and GIMP.

Additive colour starts with darkness and adds light to create colour — used by phone, TV, and computer screens (RGB). Subtractive colour starts with white and absorbs light through ink, paint, or dye — used by printers and traditional painting (CMYK, RYB).

In paint or ink, mixing all primaries (cyan + magenta + yellow, or red + yellow + blue) gives a near-black brown — true black usually requires black pigment. In light, the absence of all light is black.

In additive colour (light), red + green + blue at full intensity together make white. In subtractive colour (paint or ink), no combination of pigments makes pure white — white must come from the surface itself or from white pigment.

Neutral colours are subtle, low-saturation colours such as white, black, grey, beige, taupe, ivory, and cream. They do not strongly compete with other colours, which makes them ideal as backgrounds and grounding tones in design and interiors.

Pastels are pale, soft tints made by adding plenty of white to a base colour. Common examples are baby blue, mint green, blush pink, lavender, and butter yellow. They feel light, calm, and youthful.

Neon colours are extremely bright, fluorescent versions of standard hues — electric pink, lime green, neon orange, hot magenta. Fluorescent pigments absorb invisible ultraviolet light and re-emit it as visible light, so they look brighter than the colours around them.

As a colour name (not a metal), gold is a metallic shade of yellow with brown or orange undertones. Its standard hex value is #FFD700 — though true metallic gold also relies on shine and reflection that flat colour can't reproduce.

Each year Pantone announces a "Colour of the Year" intended to capture the cultural mood and influence design, fashion, and branding for the year ahead. Recent picks include Viva Magenta (2023), Peach Fuzz (2024), and Mocha Mousse (2025).

Red is the most universal colour of love — used in roses, hearts, and Valentine's Day imagery. Pink also represents love, particularly its tender, romantic, or affectionate forms; deep red leans passionate.

Yellow is most often linked to happiness — it is the colour of sunshine, smiley faces, and the optimism emoji. Orange is a close second and is sometimes preferred because it feels warmer without yellow's harshness.

Colour is how the brain interprets different wavelengths of light. Three kinds of cone cells in the retina respond most strongly to red, green, and blue wavelengths; the brain combines those signals into the millions of colours we experience.