Woocommerce Produt page options drop down

Hi there I'm using the "out of the box" black background with white text for the site. On products with drop down options, the white text is almost indistinguishable from the light grey background. See this page https://alexandriablaelock.com/cup-of-tea-and-sit-down-dark-t-shirt-womens-fit/. I've unsuccessfully tried several css fixes - would you please let me know what I need to do. Thanks Alex