Requirement

Solution

Code

// Allow shortcodes in ACF fields
add_filter('acf/format_value/type=textarea', 'do_shortcode');
add_filter('acf/format_value/type=text', 'do_shortcode');

/**
 * Add shortcode [turquoise]
 */
add_shortcode( 'turquoise' , 'accent_shortcode' );
function accent_shortcode($atts, $content) {
    return ''.esc_html($content).'';
}

FOR CSS You can use 
span.text-turquoise {   color: #37C3D0!important;}

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