<aura:attribute name="Impact1Title" type="Aura.Component[]">
    <div class="red">
        <lightning:outputField variant="label-hidden" fieldName="Project_Title__c" class="red" />
    </div>
    <ul>
        <li class="red">I'm red.</li>
    </ul>
</aura:attribute>


.THIS .red {
background-color: red;
font-size:5rem;}

                    <aura:if isTrue="{!not(empty('Impact_1__c'))}">
                    <lightning:card title="{!v.Impact1Title}" iconName="action:approval" class="cards" />
                </aura:if>