This simple trick of combining images and masks allows you to implement branding and corporate identity guidelines in a Moodle course. You can also create self-explanatory activity images quickly. Instead of searching matching pictures, just use generic images and make them individual icons or logos with masks.
Examples of using masks in courses:
Free download: Masks package
With designer, you can use masks to design your activities and sections. Masks can be placed over color areas or images to cover specific areas. This also works with transparencies, so that areas of an image are shown semi-transparent and others completely or not at all.Use masks for branding and place your logo on images. In addition, masks are suitable for using icons to make it obvious what the activity is about. Numbering is also very easy to implement.
This is how simple masks work: black areas are displayed, transparent areas are hidden.
Free download of masks package here.