Pote.Harmonies (Pote v1.0.0)

Color harmony generation based on color theory principles.

All functions take an RGB tuple and return lists of RGB tuples. Operations are purely mathematical — no I/O, no state.

Supported Harmonies

Complementary: Color opposite on the wheel (180°)
Analogous: Adjacent colors (±30°)
Triad: Three colors equidistant at 120°
Square: Four colors at 90° intervals
Monochromatic: Lightness variations of the same hue
Split Complementary: Complement ± flanking colors
Compound: Complement plus analogous neighbors

Type aliases defined here reference the canonical types in Pote.

Usage

iex> Pote.Harmonies.complementary({255, 87, 51})
[{51, 219, 255}]

iex> Pote.Harmonies.triad({255, 87, 51})
[{51, 255, 87}, {87, 51, 255}]

Summary

Types

rgb()

Functions

analogous(rgb)

Returns analogous colors (±30° adjacent on the wheel).

analogous(rgb, angle)

Returns the analogous colors with custom angle.

complementary(rgb)

Returns the complementary color (opposite on the hue wheel, +180°).

compound(rgb)

Returns compound (double complementary) harmony colors.

darker(arg, amount \\ 0.2)

Darkens a color by mixing it with black.

lighter(arg, amount \\ 0.2)

Lightens a color by mixing it with white.

monochromatic(rgb, steps \\ 5)

Returns monochromatic variations (same hue, different lightness).

split_complementary(rgb)

Returns split complementary colors.

square(rgb)

Returns square harmony colors (four colors equally spaced at 90°).

triad(rgb)

Returns the triad colors (three colors equally spaced at 120°).

Types

rgb()

@type rgb() :: Pote.rgb()

Functions

analogous(rgb)

@spec analogous(rgb()) :: [rgb()]

Returns analogous colors (±30° adjacent on the wheel).

Returns 2 colors: one at -30° and one at +30°.

Examples

iex> analogous({255, 0, 0})
[{255, 128, 0}, {255, 0, 128}]

analogous(rgb, angle)

@spec analogous(rgb(), float()) :: [rgb()]

Returns the analogous colors with custom angle.

Parameters

rgb - RGB color tuple
angle - Angle in degrees (default: 30)

Returns

List of 2 RGB color tuples

complementary(rgb)

@spec complementary(rgb()) :: [rgb()]

Returns the complementary color (opposite on the hue wheel, +180°).

Examples

iex> complementary({255, 0, 0})
[{0, 255, 255}]

compound(rgb)

@spec compound(rgb()) :: [rgb()]

Returns compound (double complementary) harmony colors.

Combines complementary and analogous: produces 4 colors forming two complementary pairs offset by 30°.

Examples

iex> compound({255, 0, 0}) |> length()
4

darker(arg, amount \\ 0.2)

@spec darker(rgb(), float()) :: rgb()

Darkens a color by mixing it with black.

Parameters

rgb - Source color
amount - Amount to darken (0.0–1.0, default: 0.2)

Examples

iex> darker({200, 200, 200}, 0.5)
{100, 100, 100}

lighter(arg, amount \\ 0.2)

@spec lighter(rgb(), float()) :: rgb()

Lightens a color by mixing it with white.

Parameters

rgb - Source color
amount - Amount to lighten (0.0–1.0, default: 0.2)

Examples

iex> lighter({100, 100, 100}, 0.5)
{178, 178, 178}

monochromatic(rgb, steps \\ 5)

@spec monochromatic(rgb(), pos_integer()) :: [rgb()]

Returns monochromatic variations (same hue, different lightness).

Generates steps variations evenly distributed in lightness from 20% to 80%.

Parameters

rgb - Source color
steps - Number of variations to generate (default: 5)

Examples

iex> monochromatic({255, 0, 0}, 3) |> length()
3

split_complementary(rgb)

@spec split_complementary(rgb()) :: [rgb()]

Returns split complementary colors.

Takes the complement (180°) then flanks it with ±30°. Returns 2 colors: complement-30° and complement+30°.

Examples

iex> split_complementary({255, 0, 0}) |> length()
2

square(rgb)

@spec square(rgb()) :: [rgb()]

Returns square harmony colors (four colors equally spaced at 90°).

Returns 3 additional colors (the original is implied as the first).

Examples

iex> square({255, 0, 0}) |> length()
3

triad(rgb)

@spec triad(rgb()) :: [rgb()]

Returns the triad colors (three colors equally spaced at 120°).

Returns 2 additional colors (the original is implied as the third).

Examples

iex> triad({255, 0, 0}) |> length()
2