Hi Dogsbody,
I Think it is still possible to gain a CPL and instructors rating with CVD and with the daytime only restriction. Of course the instructor rating is the only thing you're gonna want to get as theres no point in having a CPL and expecting airlines to take interest in you as it won't happen. You'll need the ATPl anyway. On the other hand I think you can only get a CPL if you pass the class 1 medical. Correct me as necessary.
However you need to ask yourself will it be worth going through the process and monetary issues just to get an instructors rating trying to get a job in an already highly competitive industry. Where flying schools would perhaps find it more economically sound to hire someone without any restrictions.
Sorry this is by no means a pop at you as i'm in exactly the same shoes you're in. In fact I should be off to Cardiff uni next week to look at some lanterns and get a professionals opinion on my colour vision.
Only then will I go to Gatwick to try and pass the lantern to get the class 1. I think this is my only hope of ever flying professsionally and as an income earning career. If I don't pass the class 1 then i'll accept the fact that i'll only ever fly in a recreational sense. Untill gene therapy advances somewhat anyway.
I stand to be corrected on the 'getting a CPL' even though you're colour blind issue though. I think you can in practice so long as you pass the class 1. If you can get the class 1 then there shouldn't be anything stopping you going further anyway.
Hope my opinions aren't taken badly.
EDIT>> 2close beat me to it and his advice is much better than mine.