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RGB Color Space

RGB (Red, Green, Blue) is the most common color space for digital displays, web colors, and digital images. It's an additive color model where colors are created by combining different intensities of red, green, and blue light.

Channels​

RGB has three channels:

  • r (Red): Intensity of red light
  • g (Green): Intensity of green light
  • b (Blue): Intensity of blue light

Channel Ranges​

All channels have the same range:

  • Minimum: 0 (no color)
  • Maximum: 255 (full intensity)

Default Values​

All channels default to 0 when not specified, resulting in black (rgb(0, 0, 0)).

Creating RGB Colors​

use Negarity\Color\Color;

// Create an RGB color
$color = Color::rgb(255, 100, 50);

// Create with individual channel access
$red = Color::rgb(255, 0, 0);
$green = Color::rgb(0, 255, 0);
$blue = Color::rgb(0, 0, 255);

Working with RGB Channels​

Getting Channel Values​

$color = Color::rgb(255, 128, 64);

$r = $color->getR();  // 255
$g = $color->getG();  // 128
$b = $color->getB();  // 64

Checking Channel Existence​

use Negarity\Color\ColorSpace\RGB;

RGB::hasChannel('r');  // true
RGB::hasChannel('g');  // true
RGB::hasChannel('b');  // true
RGB::hasChannel('a');  // false (RGBA has alpha)

Getting Channel Defaults​

use Negarity\Color\ColorSpace\RGB;

RGB::getChannelDefaultValue('r');  // 0
RGB::getChannelDefaultValue('g');  // 0
RGB::getChannelDefaultValue('b');  // 0

Getting All Channels​

use Negarity\Color\ColorSpace\RGB;

RGB::getChannels();  // ['r', 'g', 'b']

Validation​

RGB automatically validates channel values:

use Negarity\Color\Color;
use Negarity\Color\Exception\InvalidColorValueException;

try {
    // This will throw InvalidColorValueException
    $color = Color::rgb(300, 100, 50);  // R value exceeds 255
} catch (InvalidColorValueException $e) {
    // Handle error
}

Use Cases​

  • Web Development: CSS colors, HTML color codes
  • Digital Images: Most image formats use RGB
  • Screen Display: All modern displays use RGB
  • Color Picking: Most color pickers default to RGB
  • Gaming: Game engines typically work in RGB

Color Space Information​

use Negarity\Color\ColorSpace\RGB;

RGB::getName();  // "rgb"
RGB::getChannels();  // ['r', 'g', 'b']
RGB::supportsIlluminant();  // false
RGB::supportsObserver();  // false

See Also​