Whitelabel,
In Austrlalia if you do not meet the standard for colour vision your class 1 medical will be endorsed Up to CPL and for Australian airspace only.
I don't have the link handy but do a search for Dr Arthur Pape and the work he did in taking CASA to the Administrative Appeals Tribunal and winning. He is also a colour defective pilot but had the balls to take the authrority with some very sound arguments. Result being a lot of us colour defective can now work as commercial pilots, obtain night and MECIR in Australia where before we were restricted to Pvt, Day VFR only. You still must meet the minimum standard though to obtain an ATPL.
The following link will give you a good insight into the colour test procedures here.
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CASA Designated Aviation Medical Examiners Handbook
A friend who is currently working in UK also has the same degree of colour deficiency as myself ie, can't pass jack schidt in the colour tests but does now have a JAR medical which allows him to fly IFR but only during daylight. Which seems a little silly to me given that the reduced visibility in crappy weather would be far more difficult in terms of obtaining any coloured visual cues, such as PAPI lighting, upon breaking out of cloud than flying on a clear star filled night