Registers color-related attributes and generates CSS classes/inline styles for text, background, and gradient colors.

Source: wp-includes/block-supports/colors.php
Since: 5.6.0

Support Key

supports.color

Can be true (all color features) or an object:

Note: text and background default to true when color support is an array and the key is not explicitly set.

Registered Attributes

Functions

wp_register_colors_support()

function wp_register_colors_support( WP_Block_Type $block_type )

Since: 5.6.0
Since: 6.1.0 Improved $color_support assignment optimization.
Access: private

wp_apply_colors_support()

function wp_apply_colors_support( WP_Block_Type $block_type, array $block_attributes ): array

Since: 5.6.0
Since: 6.1.0 Implemented the style engine to generate CSS and classnames.
Access: private

Processing:

1. Checks top-level serialization skip for color
2. For text: uses var:preset|color|{slug} for preset, custom from style.color.text
3. For background: uses var:preset|color|{slug} for preset, custom from style.color.background
4. For gradient: uses var:preset|gradient|{slug} for preset, custom from style.color.gradient
5. Each feature checks individual serialization skip
6. Delegates to wp_style_engine_get_styles() with convert_vars_to_classnames => true

Returns: Array with class and/or style.

Generated CSS

Via wp_style_engine_get_styles() with convert_vars_to_classnames:

Classes (examples):

• has-text-color, has-{slug}-color
• has-background, has-{slug}-background-color
• has-{slug}-gradient-background

Inline styles (for custom values):

• color: #ff0000
• background-color: #00ff00
• background: linear-gradient(...)

Registration

WP_Block_Supports::get_instance()->register(
    'colors',
    array(
        'register_attribute' => 'wp_register_colors_support',
        'apply'              => 'wp_apply_colors_support',
    )
);