If you're borderline with the colour vision, you might be able to pass the
lantern test thingy, in which case you can have a Class 1 medical
certificate
after all.

I always heard the lantern test was harder than the paper tests. Here in
the US, one can get a waiver if they go to a control tower with an FAA rep
and correctly interpret light gun signals - maybe there is a similar thing
there?