I am using the Essential theme (v.220.127.116.11 (Build: 2015040900)) in Moodle v2.8.10 (Build: 20160111), although I also have a test environment with Moodle v3.0.2 and Essential theme v 18.104.22.168 (Build: 2016010204) that has the same problem.
When a resource or activity is hidden, the font colour is changed to light grey and has insufficient contrast to be able to be read easily. This is a problem for accessibility compliance and also just for general readability of the site.
There is an even greater problem when an activity or resource is hidden within a hidden section.
We use hidden resources regularly to provide information for teachers about the delivery of a course or unit. This information should not ever be visible to students. We need to hide the individual activities and resources (in the hidden section) so that students cannot navigate to an activity or resource using the 'This course' link in the menu bar, which we have found is active even if a resource or activity is hidden.
Is there a way to change the CSS in our theme (and maybe in core) so that the text and background colours are reversed for hidden resources e.g. white text on a black background, rather than using a faded grey font to indicate a resource is hidden? Or does anyone have a better suggestion to make these hidden activities and resources accessible?