Fixes PHP warnings on repeatable ColorPicker with an array as default

includes/CMB2_Utils.php

@@ -589,6 +589,7 @@ public static function concat_attrs( $attrs, $attr_exclude = array() ) {
 		foreach ( $attrs as $attr => $val ) {
 			$excluded = in_array( $attr, (array) $attr_exclude, true );
 			$empty    = false === $val && 'value' !== $attr;
+			$val 	  = is_array( $val ) ? implode( ',', $val ) : $val;
 			if ( ! $excluded && ! $empty ) {
 				// if data attribute, use single quote wraps, else double.
 				$quotes = self::is_data_attribute( $attr, 'data-' ) ? "'" : '"';

includes/types/CMB2_Type_Colorpicker.php

@@ -35,19 +35,7 @@ public function __construct( CMB2_Types $types, $args = array(), $value = '' ) {
 	public function render( $args = array() ) {
 		$meta_value = $this->value ? $this->value : $this->field->escaped_value();
 
-		$hex_color = '(([a-fA-F0-9]){3}){1,2}$';
-		if ( preg_match( '/^' . $hex_color . '/i', $meta_value ) ) {
-			// Value is just 123abc, so prepend #
-			$meta_value = '#' . $meta_value;
-		} elseif (
-			// If value doesn't match #123abc...
-			! preg_match( '/^#' . $hex_color . '/i', $meta_value )
-			// And value doesn't match rgba()...
-			&& 0 !== strpos( trim( $meta_value ), 'rgba' )
-		) {
-			// Then sanitize to just #.
-			$meta_value = '#';
-		}
+		$meta_value = self::sanitize_color( $meta_value );
 
 		wp_enqueue_style( 'wp-color-picker' );
 
@@ -69,6 +57,44 @@ public function render( $args = array() ) {
 		return parent::render( $args );
 	}
 
+	/**
+	 * Sanitizes the given color, or array of colors.
+	 *
+	 * @since 2.7.1
+	 *
+	 * @param string|array $color The color or array of colors to sanitize.
+	 *
+	 * @return string|array The color or array of colors, sanitized.
+	 **/
+	public static function sanitize_color( $color ) {
+
+		if ( is_array( $color ) ) {
+
+			$color = array_map( 'CMB2_Type_Colorpicker::sanitize_color', $color );
+
+		} else {
+
+			// Regexp for hexadecimal colors
+			$hex_color = '(([a-fA-F0-9]){3}){1,2}$';
+
+			if ( preg_match( '/^' . $hex_color . '/i', $color ) ) {
+				// Value is just 123abc, so prepend #
+				$color = '#' . $color;
+			} elseif (
+				// If value doesn't match #123abc...
+				! preg_match( '/^#' . $hex_color . '/i', $color )
+				// And value doesn't match rgba()...
+				&& 0 !== strpos( trim( $color ), 'rgba' )
+			) {
+				// Then sanitize to just #.
+				$color = '#';
+			}
+
+		}
+
+		return $color;
+	}
+
 	public static function dequeue_rgba_colorpicker_script() {
 		if ( wp_script_is( 'jw-cmb2-rgba-picker-js', 'enqueued' ) ) {
 			wp_dequeue_script( 'jw-cmb2-rgba-picker-js' );