Are you a member of the CVDPA? If not, you of all people should be, and should have been for decades. CVD pilots owe Arthur Pape and people like John O’Brien, big time. Ask the CVDPA your question.
I suspect the answer to your question is that you will be culled by the CAD Test. Avmed considers that it has been unacceptably risky to allow defectives like you to exercise the privileges of an ATPL at night. You defectives achieve the same proficiency standards as non-defectives during recurrent operational testing by cheating - that is, practising so that you are proficient. It’s only through sheer luck (and the fact that you are proficient and the fact that identifying the colour of lights is no longer relevant to the safety of aircraft operations) that you have not caused a major disaster. There is a risk of you having to rely on light signals from a tower one day and mistaking the colour of those lights and landing or taking off smack into a huge chunk of aluminium painted white. An infinitesimally small risk, but one that can be mitigated by culling you. Thus the safety of air navigation demands that you be culled.