Background Colour of logo changing in header when using custom product template.

Store Design
5

Hi @jlove_1
The reason is in your theme has a style for the element use animation.

You can try follow this path:
Themes => edit code => asset => theme.css.liquid
and add this code to bottom of the file theme.css.liquid

[data-image-loading-animation] {
background-color: transparent!important;
}