I'm curious if this was used for the musical communication in Close Encounters of the Third Kind. I recall then having notes synchronized with colors, which could be the same system shown here.
May be interesting for steganography.
Been involved in music for 10+ years... first time I've heard solfege referred to as solresol. Neat!
If you read the article, they're not the same thing. Solfege is a way of teaching the notes in a major scale, while Solresol is an entire language built on top of that.