This is an alternative version of Express Stave. It reverses the 7-5 notehead color pattern so that the notes ABCDEFG (the white piano keys) are black/solid, and the sharp and flat notes (the black keys) are white/hollow. This makes it look less like a piano tablature.
In this version solid noteheads represent the notes that occur most often (ABCDEFG), especially in the more common keys that have fewer sharps or flats. This provides greater continuity with traditional notation where solid notes also occur more frequently than hollow notes (since they represent notes of smaller duration). This would probably make it easier to learn both systems and to switch back and forth between them. Keller also maintains that the B and F notes that do not touch a line are easier to draw by hand when they are solid notes.
For this version, Keller designed three original clef symbols. His F, B, and D clefs, shown here, replaced the traditional bass, treble and middle clefs respectively. (Notice how the symbols incorporate the notes F, B, and D.)
To the left of the staff a symbol is used to represent the black keys of the piano. This helps to identify the middle line of the staff as D, and the top and bottom lines as G#/Ab:
For full details, see the Express Stave page.
Source: John Keller. Express Stave, Reverse-Color version introduced January 2010.