I :heart: how we implemented the template selection using screenshot tiles instead of radios (@wesruv ++), but now in #1617 / https://github.com/backdrop/backdrop/pull/1343 where we need to use checkboxes, it doesn't look that good. The light gray border is too subtle IMO:

backdrop-issue1617-pull1343-layout_template_checkboxes_too_subtle_selected_indication

backdrop-issue1617-pull1343-layout_template_checkboxes_too_subtle_selected_indication-hovered_and_selected_while_in_focus

backdrop-issue1617-pull1343-layout_template_checkboxes_too_subtle_selected_indication-selected_while_in_focus

backdrop-issue1617-pull1343-layout_template_checkboxes_too_subtle_selected_indication-hovered_and_selected_while_out_of_focus

Here's a couple of different ways how it could look if we for example used https://github.com/backdrop/backdrop/blob/1.x/core/misc/watchdog-ok.png:

backdrop-issue1617-pull1343-layout_template_checkboxes_watchdog_ok_as_selected_indicator

GitHub Link: 
https://github.com/backdrop/backdrop-issues/issues/1824
GitHub Issue #: 
1824