The I-Collection icons were created in "line style", which became popular through recent versions of Apple's iOS. The icons are monochrome, flat and consist of thin lines which outline the contour and essential characteristics of the icon.
Next to the standard "plain" version, each icon comes in a "selected" version. In the "selected" version the shapes of the icons are filled and a contrasting blue color is used. This version can be used to indicated an alternate state, such as "selected", "clicked" or "active".