I'm a mac user, and I've used css to make my new tab page transparent like in Safari. The only way I could figure it out is:
#tabbrowser-tabpanels {
background: transparent !important;
}
But this makes the background transparent on websites that don't have a set background card/colour too. Is there a way I can isolate this to just the new tab page, or could this possibly be something we could change in about:config in future? I love the toolbar transparency. Thanks for what you do!