None of the following are working to display conditional format in the sidebar when the current page is the home page:
I added an else clause which is implemented on the home page.
In Options > Reading, I have specified a page called Home to be the front page. The slug 'home' and the page id of 13 (obtained from the URL when editing the Home page) all return false.
If I place
<?php the_ID(); ?> in the sidebar, it displays the post ids of blog posts which are also displayed (title only) by home.php (which is the template assigned to the home page).
I don't know how else to explicitly display the page id on the front end so I know I'm using the correct id.