EquiDistantColorGen​erator

Optimize your colored plots by using colors that have maximum contrast on a white background. Best for plotting in scientific publications.

%EQUIDISTANTCOLORGENERATOR Generate visually distinct, equidistant colors.

%

% [ColorMatrix, angleOnPallet] = EquiDistantColorGenerator(numberOfColors)

% [ColorMatrix, angleOnPallet] = EquiDistantColorGenerator(numberOfColors, colorSeed)

% [ColorMatrix, angleOnPallet] = EquiDistantColorGenerator(numberOfColors, colorSeed, outputType)

% [ColorMatrix, angleOnPallet] = EquiDistantColorGenerator(numberOfColors, colorSeed, outputType, plotIt)

%

% DESCRIPTION

% Returns a set of N visually distinct colors sampled (approximately)

% equidistantly from a fixed hue palette. Colors can be returned as RGB

% triples or HEX strings. Optionally supply a seed to reproduce the same

% palette across runs. Optionally display a quick preview plot.

%

% INPUTS

% numberOfColors : (required, positive integer)

% The number of colors N to generate.

%

% colorSeed : (optional, scalar numeric) [default: random seed]

% Seed used to initialize RNG for reproducible color selection. If

% empty or not provided, a random seed is chosen and printed to the

% command window so it can be reused later.

%

% outputType : (optional, char/string) [default: 'rgb']

% Output format for colors:

% 'rgb' : return N×3 double matrix with RGB values in [0,1].

% 'hex' : return N×1 cell array of '#RRGGBB' strings.

%

% plotIt : (optional, logical) [default: false]

% When true (or when no seed is provided), a simple line plot is

% shown to preview the generated colors and their order.

%

% OUTPUTS

% ColorMatrix :

% If outputType = 'rgb' -> N×3 matrix of doubles in [0,1].

% If outputType = 'hex' -> N×1 cell array of '#RRGGBB' strings.

%

% angleOnPallet : N×1 vector of hue “angles” (in degrees) corresponding

% to each returned color’s position on the internal palette.

%

% BEHAVIOR & NOTES

% • Determinism: Using the same (numberOfColors, colorSeed) pair returns

% the same ColorMatrix and angleOnPallet.

% • No seed provided: The function picks a random seed, prints it to the

% command window (e.g., “seed=1234”), and (by default) shows a preview

% plot so you can iterate until you like the palette.

% • Palette: Colors are chosen from a fixed 36-color palette spanning the

% hue circle. Indices are stepped to approximate equal spacing.

% • Legacy special case: For compatibility, if colorSeed == 0.84913 and

% numberOfColors == 4, the first three colors are fixed to a legacy set

% and the 4th is generated from the palette (see code block).

%

% EXAMPLES

% % 1) Random palette, preview shown, seed printed to command window:

% C = EquiDistantColorGenerator(5);

%

% % 2) Reproducible palette (no preview by default):

% C = EquiDistantColorGenerator(5, 897);

%

% % 3) HEX output:

% H = EquiDistantColorGenerator(6, [], 'hex');

%

% % 4) Force preview even with a seed:

% C = EquiDistantColorGenerator(4, 123, 'rgb', true);

%

% SEE ALSO

% colormap, rng, plot, hex2rgb

%

% AUTHOR

% Naveed Reza Aghamohammadi

%

% VERSION

% Initiated: 2022-12-13

% Header updated: 2025-11-13

%

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