I think that’s up to the discretion of the browser. You could try looking through Vimeo custom options or at the javascript of the Selecta theme. If that doesn’t work, you can just have a little note that says “website best viewed in Firefox.”
I’m using Selecta too and I’m wondering how you changed the color of the top bar (with your Yom logo) and how you removed the “home” link that’s there by default.
Thanks!