I wanted to remove the Refresh and Open controls that appear when hovering over a chart on a dashboard. So I added the following code to overrides_custom.css and uploaded to a new theme in JRS:
This works as expected when viewing the dashboard normally (for example, by previewing the dashboard from the designer): the Refresh and Open controls no longer appear when hovering over a chart in the dashboard. However, when embedding the dashboard with viewAsDashboardFrame=true the controls still appear when hovering over a chart.
Workaround: Update the above styles in pageSpecific.css and upload to the theme, instead of using overrides_custom.css.