Hi there!
Thanks for your query.
I have checked your site. Maybe your other pages using different template styles than the Home page, hence a different Header class. So those pages shows the white logo when the header is not sticky.
You have two options I guess. One is you can upload the same image as white logo. The other is you can use the following code in your custom CSS:
body:not(.solid-header) #sp-header .logo-image.white-logo {
display: none !important;
}
body:not(.solid-header) #sp-header .logo-image {
display: block !important;
}
Hope this will solve the issue for you!
Note: Path towards custom CSS: Extensions>Templates>Styles> Click on your current default template name then choose Template Options. Then find custom CSS within the custom code.
Best Regards