Assuming we have a race of creatures that breathe out coloured smoke, how could a system of communication or language develop that is based on the colour of said smoke?
Assume they can form sentences or concepts by breathing more than one colour at a time, and multiple colours in succession. Also assume that the creatures need to be able to communicate simple concepts to each other ( such as "follow me" "where are you going?" and "it will talk to you soon") but also can communicate more complex concepts, like love and life and death, even if simplified to more base emotions and concepts (such as 'death' in this language being 'a state of not moving or talking or breathing')
I have tried to use the colour wheel as a start and trying to break down language into colours but I didn't get father than trying to break down language into requests or questions, statements and emotions or exclamations for Red, Yellow and Blue, and trying to fill in the in between colours, including shades of the colours, with concepts and language somehow, but got to the conclusion that language itself is too complex to break down that way.
Perhaps trying to marry two forms of communication in one? Like the colours and the way programs talk to each other over TCP/IP? I am still unsure.
EDIT: I have had some pretty good answers so far but I failed to mention one thing: If possible, I want to avoid a 1-to-1 relationship between colours and letters. I don't want to make a morse code or hex type language or anything like that....I would prefer to have each colour hue and shade represent something. See the example I gave for breaking down language into questions / requests, statements and expressions or feelings...So, less so language and more a system of communication. Think sign language or Cantonese, where each letter or syllable or movement is a concept, not a letter.
Thank you for your answers.