tomloprod / colority

Colority it's a PHP library that allows you to: transform and validate colors, obtain the best contrast color (using contrast ratio from WCAG 2.0 standard), extract colors from images and more.

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🎨 About Colority

Colority is a lightweight PHP library designed to handle color transformations, validations and manipulations with ease.

It allows you to instantiate concrete objects according to the color format (RGB, HSL, Hexadecimal) and convert from one format to another.

Additionally, it lets you check if a background color meets the WCAG 2.0 accessibility standard regarding the color contrast ratio in text and UI.

Furthermore, it includes multiple functions such as the following:

• Generate the best foreground color (white, black, or from a user-provided list) for a background color, ensuring the best possible contrast ratio. (important for improving text visibility on, for example, colored badges).
• Generate a fixed color based on a string. Useful for generating a color associated with, for example, a username.
• Allows you to obtain a random color similar to a given color.

✨ Getting Started

Instantiating Color objects

You can convert value colors (strings or, additionally, depending on the color type, arrays) to specific Color objects.

/** @var RgbColor $rgbColor */
$rgbColor = colority()->fromRgb('rgb(255,255,255)');
$rgbColor = colority()->fromRgb('255,255,255'); 
$rgbColor = colority()->fromRgb([255, 255, 255]); 

/** @var HexColor $hexColor */
$hexColor = colority()->fromHex('#51B389');
$hexColor = colority()->fromHex('51B389'); 
$hexColor = colority()->fromHex('#ABC');

/** @var HslColor $hslColor */
$hslColor = colority()->fromRgb('hsl(168.31deg, 49.58%, 46.67%)');
$hslColor = colority()->fromRgb('168.31, 49.58, 46.67'); 
$hslColor = colority()->fromRgb([168.31, 49.58, 46.67]); 

If you cannot specify the original format of the value color, you can use the parse method. This will detect what type of color it is and instantiate a new object or, if the received string does not match any type of color, it will return NULL:

/** @var RgbColor|null $rgbColor */
$rgbColor = colority()->parse('rgb(255,255,255)');

/** @var HexColor|null $hexColor */
$hexColor = colority()->parse('#51B389');

/** @var HslColor|null $hslColor */
$hslColor = colority()->parse('hsl(168.31deg, 49.58%, 46.67%)');

Contrast ratio (WCAG 2.0 standard)

When you have the Color object, you will be able to use all its methods. Below, we describe two of them related to the contrast ratio.

getBestForegroundColor

Returns a Color object with the most suitable foreground color (using the Luminosity Contrast Ratio algorithm).

You can pass an array with Color objects as a parameter, so it chooses the foreground color with the best contrast ratio. If no parameter is specified, it will default to white or black.

/** @var HexColor $hexColor */
$hexColor = colority()->fromHex('#51B389');

/** @var HexColor $bestForegroundHexColor (black or white) */
$bestForegroundHexColor = $hexColor->getBestForegroundColor();

/** @var HexColor $bestForegroundHexColor (#A63F3F, #3FA684 or #6E3FA6) */
$bestForegroundHexColor = $hexColor->getBestForegroundColor([
    new HexColor('#A63F3F'),
    new HexColor('#3FA684'),
    new HexColor('#6E3FA6'),
]);

getContrastRatio

Returns the contrast ratio (higher is better contrast, lower is worse) between the color invoking this method and the color passed as a parameter. If no color is passed as a parameter, the contrast ratio against black as foreground will be determined.

/** @var HexColor $hexColor */
$hexColor = colority()->fromHex('#51B389');

/** @var float $contrastRatio Contrast ratio with black as the foreground color. */
$contrastRatio = $hexColor->getContrastRatio();

/** @var float $contrastRatio Contrast ratio with #3FA684 as the foreground color. */
$contrastRatio = $hexColor->getContrastRatio(new HexColor('#3FA684'));

AA & AAA WCAG levels

Below we show you how to check if a contrast ratio meets WCAG AA and AAA levels using Tomloprod\Colority\Support\Algorithms\ContrastRatioScore.

/** @var HexColor $hexColor */
$hexColor = colority()->fromHex('#51B389');

/**
 * The `getContrastRatio` method can take a `Color` object as the foreground 
 * to calculate the contrast ratio against that color. Black is used by default.
 * 
 * @var float $contrastRatio
 */
$contrastRatio = $hexColor->getContrastRatio();

/**
 * AA Level for texts
 */
$passsesAALevelForLargeText = ContrastRatioScore::passesTextAALevel(
    contrastRatio: $contrastRatio,
    largeText: true
);

$passsesAALevelForNormalText = ContrastRatioScore::passesTextAALevel(
    contrastRatio: $contrastRatio,
    largeText: false
);

/**
 * AAA Level for texts
 */
$passsesAAALevelForLargeText = ContrastRatioScore::passesTextAAALevel(
    contrastRatio: $contrastRatio,
    largeText: true
);

$passsesAAALevelForNormalText = ContrastRatioScore::passesTextAAALevel(
    contrastRatio: $contrastRatio,
    largeText: false
);
/**
 * AA Level for Graphical Objects and User Interface Components
 */
$passsesAALevelForUI = ContrastRatioScore::passesUIAALevel(
    $contrastRatio
);

Color validation

The concrete Color classes have a static method called getParser() which returns an instance of ValueColorParser.

The parse method returns a string with the value color adapted to work correctly with Colority or throws an InvalidArgumentException when it's not valid.

/** @var ValueColorParser $hexParser */
$hexParser = HexColor::getParser();

// will throw InvalidArgumentException
$valueColor = $hexParser->parse('Not a valid value color'); 

// will return #FFFFFF
$valueColor = $hexParser->parse('#FFF');

You can use the specific parser for any type of color:

$hslParser = HslColor::getParser();

$rgbParser = RgbColor::getParser();

$hexParser = HexColor::getParser();

Color conversion

Colority allows you to convert a Color object to any other Color object of the desired format.

/** @var HexColor|null $hexColor */
$hexColor = colority()->fromHex('#51B389');

/** @var HexColor $hexColor */
$hexColor = $hexColor->toHex();

/** @var RgbColor $rgbColor */
$rgbColor = $hexColor->toRgb();

/** @var HslColor $hslColor */
$hslColor = $hexColor->toHsl();

Color utilities

getImageColors

It allows you to obtain the colors detected in an image. As the first argument, the path to the image must be provided.

It has an optional second parameter (default is 5) that specifies the number of colors to be returned.

/** @var array<RgbColor> $imageColors */
$imageColors = colority()->getImageColors(
    imagePath: __DIR__.'/image-colors.png',
    desiredNumColors: 10
);

textToColor

Generate a fixed color based on a string.

/** @var HslColor $hslColor */
$hslColor = colority()->textToColor("Hi, I'm Tomás");

🧙 Advise Useful for generating a color associated with, for example, a username, mail address, etc, since a string will always return the same color.

getSimilarColor

Allows you to obtain a random color similar (in the same color palette) to a given color.

/** @var HexColor|null $hexColor */
$hexColor = colority()->fromHex('#51B389');

/** @var HexColor|null $similarHexColor */
$similarHexColor = colority()->getSimilarColor($hexColor);

Ways of using Colority

You can use Colority either with the aliases colority()

/** @var HexColor $hexColor */
$hexColor = colority()->fromHex('#CCC');

or by directly invoking the static methods of the Colority facade:

/** @var HexColor $hexColor */
$hexColor = Colority::fromHex('#CCC');

You decide how to use it 🙂

🧱 Architecture

Colority is composed of several types of elements. Below are some features of each of these elements.

Colority

Tomloprod\Colority\Support\Facades\Colority is a facade that acts as a simplified interface for using the rest of the Colority elements.

Methods

Colority::parse(string $valueColor): Color|null

Colority::fromHex(string $hexValue): HexColor

Colority::fromRgb(string|array<int> $rgbValue): RgbColor

Colority::fromHsl(string|array<float> $hslValue): HslColor

Colority::textToColor(string $text): HslColor

Colority::getSimilarColor(Color $color, int $hueRange = 30, int $saturationRange = 10, int $lightnessRange = 10): Color

Color

All concrete color classes extend the abstract class Color. Concrete color classes:

• Tomloprod\Colority\Colors\HexColor
• Tomloprod\Colority\Colors\HslColor
• Tomloprod\Colority\Colors\RgbColor

Methods

/** @var HexColor $hexColor */
$hexColor = Colority::fromHex('#CCCCCC');

$hexColor->toHex(): HexColor;
$hexColor->toRgb(): RgbColor;
$hexColor->toHsl(): HslColor;

// Returns the value color in string format. Example: #CCCCCC
$hexColor->getValueColor(): string;

For the HslColor and RgbColor objects, you also have a method getArrayValueColor that will return the value color in array format:

/** @var RgbColor $rgbColor */
$rgbColor = Colority::fromRgb('255,255,255');

/** @var array $arrayValueColor [255,255,255] */
$arrayValueColor = $rgbColor->getArrayValueColor();

On the other hand, the HslColor object has an additional method called getValueColorWithMeasureUnits, which returns the value color, but with units of measurement (useful for, for example, using it in a CSS style):

/** @var HslColor $hslColor */
$hslColor = Colority::fromHsl('hsl(32.4, 60.48, 51.37)');

/** @var string $valueColorWithMeasureUnits hsl(32.4deg,60.48%,51.37%) */
$valueColorWithMeasureUnits = $hslColor->getValueColorWithMeasureUnits();

/** @var string $valueColor hsl(32.4,60.48,51.37) */
$valueColor = $hslColor->getValueColor(): string;

🚀 Installation & Requirements

Requires PHP 8.2+

You may use Composer to install Colority into your PHP project:

composer require tomloprod/colority

🧑‍🤝‍🧑 Contributing

Contributions are welcome, and are accepted via pull requests. Please review these guidelines before submitting any pull requests.

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Colority was created by Tomás López and open-sourced under the MIT license.