Show different header logo based on category?

Is there a way to show a different main logo in the header (top left) when browsing threads within a certain category or their sub categories? Thank you.

I believe the body includes a class category-{category here}, which you could use to change category specific CSS.

I don’t know how to execute a script after the page content have loaded (I’m interested to know that too!), but for changing the logo image, you could do this:

// in a condition like if category == "somecategory" then…
document.getElementById("#site-logo").src = settings.theme_uploads.logo_cat1;

where logo_cat1 is the variable name of a custom logo: