Welcome! You've made it here because of your curiosity. You must have followed one of the maqamat not available on the demo site. The full site, including 34 maqam pages, 61 jins pages, and a total of 352 ajnas, is currently in development.
The colors are arbitrary. The point of color is to create a code easily recognizable by the eye, so the jins network graphs on various pages of this site are quickly comprehensible. Every sign in a signal system is arbitrary--that is, a different possible value for any given sign could be used, without changing anything essential about the system. Yet I admit the tempting paths of synaesthesia called me. Who can Resist a Rainbow? How better to capture the spectrum of melodic flavors that are ajnas? But this synaesthesia, like onomatopoeia in language, doesn't contradict the arbitrary nature of the system as a whole, even as its mnemonic power lends a distinctiveness to individual items.