Hello,

Thank you very much for choosing our theme and for contacting us.
Please add this code to the Theme Settings > Custom CSS > Global:

body .product_meta .sku_wrapper {
    display: inline-block;
    margin: 0 1px;
    color: red;
    font-weight: 400;
    font-size:30px;
}

You can change the style as per your needs.

If you have any questions please feel free to contact us.

Best Regards