Daniel,
Each ICAO state has its own regulations. In JAA (Europe) we have very restrictive regulations on Colour Vision and in fact until late 2009 the UK CAA has the most liberal of all EU states in allowing a restricted class 1 medical.
The USA has a very liberal view of colour vision - see the FAA website for details. Canada is similar and Australia has it's own regulations after a law suite by Dr Pape.
In short the ICAO has no definitave answers for CVD and a medical for a professional licence - I say professional licence as in JAA land it is a class 1 medical, but in the US you can fly on CPL with class 2.
The destinction between states is very different and you need to pinpoint where you want to fly and under which licence. I'm sure that when you can answer these questions we will be able to give you very specific answers.
In short there is no ICAO medical - each state will view it as its own and this will vary much between ICAO states. As I said you need to be specific where you want to fly and under which licence.
Congratulations on joining this forum and I wish you all the best in your future flying.