<div class="uk-section uk-height-viewport uk-flex uk-flex-middle">
    <div class="uk-container uk-flex-auto">

        <style>
            .test { height: 250px; }
        </style>

        <div class="uk-child-width-1-3@m" uk-grid>

            <div>
                <div class="uk-panel uk-background-muted test">
                    <h2 class="uk-h5 uk-position-center">Muted</h2>
                </div>
            </div>

            <div>
                <div class="uk-panel uk-background-primary uk-light uk-light test">
                    <h2 class="uk-h5 uk-position-center">Primary</h2>
                </div>
            </div>

            <div>
                <div class="uk-panel uk-background-secondary uk-light test">
                    <h2 class="uk-h5 uk-position-center">Secondary</h2>
                </div>
            </div>

        </div>

    </div>
</div>