How to change style of getChildHtml(‘order_totals’)?

I’m trying to change the background color (from light grey to white) of several <th> and <td> in our new sales order email, below:

The HTML is being outputted by this method:

<tfoot class="order-totals">
    <?= $block->getChildHtml('order_totals') ?>
</tfoot>

The template totals.phtml contains the logic and HTML but I don’t see the inline styles responsible for the background in the above picture.

The path to totals.phtml is /magento/vendor/magento/module-sales/view/frontend/templates/order

I see the attributes are being assigned with this method:

<th <?= /* @noEscape */ $block->getLabelProperties() ?> scope="row">

Does anyone know where these inline styles are being injected? Thank you.