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function is not described

sanitize_hex_color_no_hash() WP 3.4.0

Sanitizes a hex color without a hash. Use sanitize_hex_color() when possible.

Saving hex colors without a hash puts the burden of adding the hash on the UI, which makes it difficult to use or upgrade to other color types such as rgba, hsl, rgb, and html color names.

Returns either '', a 3 or 6 digit hex color (without a #), or null.

No Hooks.

Return

String/null.

Usage

sanitize_hex_color_no_hash( $color );
$color(string) (required)

Code of sanitize hex color no hash: wp-includes/formatting.php VER 5.0.3

<?php
function sanitize_hex_color_no_hash( $color ) {
	$color = ltrim( $color, '#' );

	if ( '' === $color ) {
		return '';
	}

	return sanitize_hex_color( '#' . $color ) ? $color : null;
}