"light style" is the Lynx site scheme. Go to "manage account", the "display" tab, and pick Lynx, and any pages that disply in site scheme will display in light style. On that same page, you can check "View comment pages from your Reading Page in your own style", and make other people's comment pages show up in your style.

If you haven't set comment pages in your style to appear in site scheme yet, you can do that by going to the very bottom of the 'customize journal style page', and you should see a checkbox labelled "Show entry pages in my journal style rather than the app style". Check that box. Now all comment pages from your reading page should show up in light style.