array(
    'type'  => 'rgba-color-picker',
    'value' => 'rgba(255,0,0,0.5)',
    'attr'  => array( 'class' => 'custom-class', 'data-foo' => 'bar' ),
    // palette colors array
    'palettes' => array( '#ba4e4e', '#0ce9ed', '#941940' ),
    'label' => __('Label', '{domain}'),
    'desc'  => __('Description', '{domain}'),
    'help'  => __('Help tip', '{domain}'),
)