WordPress Color Utils

A lean WordPress library for essential color operations. Provides practical utilities for color conversions, adjustments, and accessibility helpers with self-contained methods and robust error handling.

Installation

composer require arraypress/wp-color-utils

Quick Start

use ArrayPress\ColorUtils\Color;

// Convert colors
$rgb  = Color::hex_to_rgb( '#ff0000' ); // ['red' => 255, 'green' => 0, 'blue' => 0]
$hex  = Color::rgb_to_hex( 255, 0, 0 ); // "#ff0000"
$rgba = Color::hex_to_rgba( '#ff0000', 0.5 ); // "rgba(255, 0, 0, 0.50)"

// Get contrast color for accessibility
$text_color = Color::get_contrast_color( '#ff0000' ); // "#ffffff"

// Adjust brightness
$lighter = Color::lighten( '#ff0000', 20 ); // "#ff3333"
$darker  = Color::darken( '#ff0000', 20 ); // "#cc0000"

Features

Core Conversions

• Hex ↔ RGB: Convert between hex codes and RGB values
• Hex to RGBA: Generate CSS rgba() strings with alpha transparency
• Color Validation: Sanitize and validate hex color codes

Accessibility Helpers

• Contrast Colors: Get optimal black/white text color for any background
• Brightness Detection: Check if colors are dark or light

Color Adjustments

• Lighten/Darken: Adjust color brightness by percentage
• Color Mixing: Blend two colors together
• Random Colors: Generate random hex colors

Self-Contained & Robust

• Each method handles its own validation
• Graceful error handling with null returns
• No external dependencies
• Support for 3-character hex codes (#f00 → #ff0000)

API Reference

Color Conversions

hex_to_rgb(string $hex): ?array

Convert hexadecimal color to RGB array.

$rgb = Color::hex_to_rgb( '#ff0000' );  // ['red' => 255, 'green' => 0, 'blue' => 0]
$rgb = Color::hex_to_rgb( 'f00' );      // ['red' => 255, 'green' => 0, 'blue' => 0]
$rgb = Color::hex_to_rgb( 'invalid' );  // null

rgb_to_hex(int $red, int $green, int $blue): string

Convert RGB values to hexadecimal color.

$hex = Color::rgb_to_hex( 255, 0, 0 );     // "#ff0000"
$hex = Color::rgb_to_hex( 128, 128, 128 ); // "#808080"
$hex = Color::rgb_to_hex( 300, - 10, 0 );   // "#ff0000" (clamped to 0-255)

hex_to_rgba(string $hex, float $alpha = 1.0): ?string

Convert hex color to CSS rgba() string.

$rgba = Color::hex_to_rgba( '#ff0000', 0.5 );   // "rgba(255, 0, 0, 0.50)"
$rgba = Color::hex_to_rgba( '#0000ff' );        // "rgba(0, 0, 255, 1.00)"
$rgba = Color::hex_to_rgba( 'invalid', 0.5 );   // null

Accessibility Helpers

get_contrast_color(string $hex_color): string

Get optimal text color (black or white) for a background color.

$text = Color::get_contrast_color( '#ffffff' ); // "#000000"
$text = Color::get_contrast_color( '#000000' ); // "#ffffff"
$text = Color::get_contrast_color( '#ff0000' ); // "#ffffff"
$text = Color::get_contrast_color( '#ffff00' ); // "#000000"

is_dark(string $hex_color): bool

Check if a color is considered dark.

$dark = Color::is_dark( '#000000' ); // true
$dark = Color::is_dark( '#ffffff' ); // false
$dark = Color::is_dark( '#ff0000' ); // true
$dark = Color::is_dark( 'invalid' ); // false

is_light(string $hex_color): bool

Check if a color is considered light.

$light = Color::is_light( '#ffffff' ); // true
$light = Color::is_light( '#000000' ); // false
$light = Color::is_light( '#ffff00' ); // true

Color Adjustments

lighten(string $hex_color, int $percent = 10): ?string

Lighten a color by percentage.

$lighter = Color::lighten( '#ff0000', 20 );  // "#ff3333"
$lighter = Color::lighten( '#000000', 50 );  // "#808080"
$lighter = Color::lighten( 'invalid', 20 );  // null

darken(string $hex_color, int $percent = 10): ?string

Darken a color by percentage.

$darker = Color::darken( '#ff0000', 20 );   // "#cc0000"
$darker = Color::darken( '#ffffff', 50 );   // "#808080"
$darker = Color::darken( 'invalid', 20 );   // null

mix(string $color1, string $color2, float $ratio = 0.5): ?string

Mix two colors together.

$mixed = Color::mix( '#ff0000', '#0000ff', 0.5 ); // "#800080" (purple)
$mixed = Color::mix( '#000000', '#ffffff', 0.3 ); // "#4d4d4d"
$mixed = Color::mix( '#ff0000', 'invalid', 0.5 ); // null

Utilities

sanitize_hex(string $hex_color): ?string

Clean and validate hex color codes.

$clean = Color::sanitize_hex( 'ff0000' );   // "#ff0000"
$clean = Color::sanitize_hex( '#FF0000' );  // "#ff0000"
$clean = Color::sanitize_hex( 'f00' );      // "#ff0000"
$clean = Color::sanitize_hex( 'invalid' );  // null

random(): string

Generate a random hex color.

$random = Color::random(); // "#a3b2c1" (example)

Use Cases

Theme Customization

use ArrayPress\ColorUtils\Color;

// Get user's primary color
$primary = get_theme_mod( 'primary_color', '#007cba' );

// Generate theme color variations
$theme_colors = [
	'primary'         => $primary,
	'primary_dark'    => Color::darken( $primary, 15 ),
	'primary_light'   => Color::lighten( $primary, 15 ),
	'text_on_primary' => Color::get_contrast_color( $primary )
];

// Use in CSS
echo "
.button {
    background: {$theme_colors['primary']};
    color: {$theme_colors['text_on_primary']};
}
.button:hover {
    background: {$theme_colors['primary_dark']};
}
";

Dynamic CSS Generation

// Generate CSS with transparency
$accent_color  = '#e74c3c';
$overlay_color = Color::hex_to_rgba( $accent_color, 0.8 );

echo "
.hero-overlay {
    background: {$overlay_color};
}
";

Form Validation

// Sanitize color input
$user_color = Color::sanitize_hex( $_POST['brand_color'] );
if ( $user_color ) {
	update_option( 'site_accent_color', $user_color );
} else {
	wp_die( 'Invalid color format' );
}

Accessibility Compliance

// Ensure readable text color
$bg_color   = get_option( 'section_background', '#ffffff' );
$text_color = Color::get_contrast_color( $bg_color );

echo "<div style='background: {$bg_color}; color: {$text_color};'>";
echo "This text will always be readable!";
echo "</div>";

Color Palette Generation

// Create a cohesive color scheme
$base_color = '#3498db';

$palette = [
	'primary'   => $base_color,
	'secondary' => Color::mix( $base_color, '#e74c3c', 0.3 ),
	'success'   => Color::mix( $base_color, '#27ae60', 0.4 ),
	'light'     => Color::lighten( $base_color, 40 ),
	'dark'      => Color::darken( $base_color, 30 )
];

WordPress Customizer Integration

// In customizer settings
function register_color_controls( $wp_customize ) {
	$wp_customize->add_setting( 'header_bg_color', [
		'sanitize_callback' => function ( $color ) {
			return Color::sanitize_hex( $color ) ?: '#ffffff';
		}
	] );
}

// In theme output
function output_dynamic_styles() {
	$header_bg   = get_theme_mod( 'header_bg_color', '#ffffff' );
	$header_text = Color::get_contrast_color( $header_bg );

	echo "<style>
    .site-header {
        background-color: {$header_bg};
        color: {$header_text};
    }
    </style>";
}

Error Handling

All methods handle invalid input gracefully:

// Invalid hex codes return null
$result = Color::hex_to_rgb( 'invalid' );  // null
$result = Color::lighten( 'notacolor', 10 ); // null

// RGB values are automatically clamped
$hex = Color::rgb_to_hex( 300, - 50, 1000 ); // "#ff00ff" (clamped to 0-255)

// Alpha values are clamped to 0-1
$rgba = Color::hex_to_rgba( '#ff0000', 2.5 ); // Uses 1.0 instead

Requirements

• PHP 7.4+
• WordPress 5.0+

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the GPL-2.0-or-later License.

Support

• Documentation
• Issue Tracker