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Introduction to Named Colors

Named colors allow you to create colors using human-readable names like "red", "blue", or "navy" instead of numeric values. Negarity Color supports named colors through a flexible registry system.

What are Named Colors?​

Named colors are predefined color values associated with common color names. Instead of remembering that red is rgb(255, 0, 0), you can simply use Color::red().

Available Color Registries​

Negarity Color comes with the VGA Named Colors registry, which includes 16 standard VGA colors:

  • white, silver, gray, black
  • red, maroon
  • yellow, olive
  • lime, green
  • aqua, teal
  • blue, navy
  • fuchsia, purple

Each named color is available in all supported color spaces (RGB, RGBA, CMYK, HSL, HSLA, HSV, Lab, LCh, XYZ, YCbCr).

Using Named Colors​

Registering a Color Registry​

Before you can use named colors, you need to register a color registry:

use Negarity\Color\Color;
use Negarity\Color\Registry\VGANamedColors;

// Register the VGA named colors
Color::addRegistry(new VGANamedColors());

Creating Colors by Name​

Once registered, you can create colors using static method calls with the color name:

// Create colors in RGB (default)
$red = Color::red();
$blue = Color::blue();
$green = Color::green();

echo $red; // "rgb(255, 0, 0)"
echo $blue; // "rgb(0, 0, 255)"
echo $green; // "rgb(0, 128, 0)"

Specifying Color Space​

You can specify which color space to use when creating named colors:

use Negarity\Color\ColorSpace\HSL;
use Negarity\Color\ColorSpace\CMYK;

// Create in HSL
$redHsl = Color::red(HSL::class);
echo $redHsl; // "hsl(0, 100, 50)"

// Create in CMYK
$blueCmyk = Color::blue(CMYK::class);
echo $blueCmyk; // "cmyk(100, 100, 0, 0)"

Working with Named Colors​

Named colors are regular Color instances, so you can use all the same methods:

$red = Color::red();

// Convert to different color spaces
$redHsl = $red->toHSL();
$redCmyk = $red->toCMYK();

// Modify the color
$lighterRed = $red->toHSL()->with(['l' => 70])->toRGB();

// Get channel values
echo $red->getR(); // 255
echo $red->getG(); // 0
echo $red->getB(); // 0

// Convert to hex
echo $red->toHex(); // "#FF0000"

Examples​

Basic Usage​

use Negarity\Color\Color;
use Negarity\Color\Registry\VGANamedColors;

Color::addRegistry(new VGANamedColors());

// Create a palette using named colors
$primary = Color::blue();
$secondary = Color::green();
$accent = Color::red();
$background = Color::white();
$text = Color::black();

Creating Color Variants​

Color::addRegistry(new VGANamedColors());

$baseColor = Color::blue();

// Create lighter and darker variants
$lightBlue = $baseColor->toHSL()->with(['l' => 70])->toRGB();
$darkBlue = $baseColor->toHSL()->with(['l' => 30])->toRGB();

Working with Different Color Spaces​

Color::addRegistry(new VGANamedColors());

// Get named color in different spaces
$redRgb = Color::red();
$redHsl = Color::red(\Negarity\Color\ColorSpace\HSL::class);
$redCmyk = Color::red(\Negarity\Color\ColorSpace\CMYK::class);

// All represent the same color
echo $redRgb->toHex(); // "#FF0000"
echo $redHsl->toHex(); // "#FF0000"
echo $redCmyk->toHex(); // "#FF0000"

Error Handling​

If you try to use a named color that doesn't exist in the registry, an exception will be thrown:

Color::addRegistry(new VGANamedColors());

try {
    $color = Color::magenta(); // Throws InvalidArgumentException
} catch (\InvalidArgumentException $e) {
    echo "Named color 'magenta' not found in registry\n";
}

Registering Custom Color Registries​

You can create and register your own color registries. See the Extending the Library - Adding Color Names section for detailed instructions.

Multiple Registries​

You can register multiple registries. The library will search through them in the order they were registered:

Color::addRegistry(new VGANamedColors());
Color::addRegistry(new MyCustomColors());

// Will search VGANamedColors first, then MyCustomColors
$color = Color::red();

Benefits of Named Colors​

  • Readability: Code is more self-documenting with names like Color::blue() instead of Color::rgb(0, 0, 255)
  • Consistency: Ensures you use the exact same color values across your application
  • Maintainability: Change a color definition in one place (the registry) and it updates everywhere
  • Multi-space Support: Each named color is available in all color spaces

Next Steps​