when I visualize a VisualForce page rendered as PDF on the Salesforce mobile application the image of the checkboxes appears with a black background. I used the following two versions of markup, but neither worked:
<img src="https://mydomain.my.salesforce.com/img/checkbox_checked.gif" style="background-color:white;"/>
<img src="/img/checkbox_unchecked.gif" style="background-color: white;"/>
background: #ffffff;
to make sure it's not the attribute ofbackground-color
that is giving you issues. – nbrown Jun 10 '20 at 12:33