If you have selected Responsive (automatic size) to display the Adsense ads on your website, you may come across problem where some of the Adsense ads may show light yellow background if the size of the ad is smaller than the div you placed it.  The easier fix is to place the following css code in style.css within your theme file:

ins {
     background-color: #FFFFFF !important;
}

If you don’t know where the theme stylesheet style.css is located, it’s located in WordPress Admin menu – Appearance | Editor, and look for stylesheet file to insert the code.

Leave a comment below and let me know if that helps.