Picture of the 2D pattern of guitar keys when they are arranged to be linked together by repeating chords

Above you can see the way that the chords of all the guitar keys fit together like puzzle pieces. Maybe someone can explain it to me. But it seems that all the keys are somehow linked in music. We know that you can play the same song in different keys, by simply substituting the corresponding chords of the 2 keys between which you are transposing. Click on the picture to magnify it.

The following keys seem to be stringed together sequentially in a repeating pattern running from top to bottom next to each other:
D-G-C-F-Bb-Eb-G#-C#-F#-B-E-A-D-G-C-F-Bb-Eb-G#

There must be a reason why it is so. Maybe it is sorted in order of increasing overall tone?

I would like to get feedback from anybody who finds this interesting...

There is another site who looked at colour coding guitar chords:
http://www.tobinmusic.co.uk/articles/guitarmethod.htm