A dark theme is available with the mzp-t-dark theme class. This example omits a description and includes a CTA button.

<section class="mzp-c-callout mzp-t-dark">
    <div class="mzp-l-content">
        <div class="mzp-c-callout-content">
            <h1 class="mzp-c-callout-title">A Headline With 30 Characters</h1>
        </div>
        <div class="mzp-c-callout-cta">
            <button class="mzp-c-button mzp-t-dark" type="button">Call to Action</button>
        </div>
    </div>
</section>