These signs have the same meaning as the syllables in movabe-do Solfège.
A left semicircle represents the root, a dot the third, and a right semicircle the fifth of a triad.
The dominant is indicated above, the subdominant below.
This way there are unique signs also for the three tones (ti, re, fa) that are not part of a tonic chord.

la	ti	do	re	mi	fa	so

Signs for the same degree in a scale have the same pattern in the respective color.
E.g. the 6th tone of a scale is the third of the subdominant.

	1	2	3	4	5	6	7	8
major
minor

The two semitone steps in the major and minor scale are marked with a missing border.