But I've always seen it like this:
Color blind because you can't see the many shades of life; you have a black and white thinking mindset. You see things as either all positive or all negative. Or It's about that lack of diversity and variation that makes an individual's life sustainable. One day you're pure one day you're the opposite. The world sees you the same way.
So being black and white or colorblind isn't about something that typically follows birth and will inevitably be outgrown. If it was about being colorblind at birth, which will definitely be outgrown; what's the point of the rest of the song and all the subsequent emotions poured into longing for things to change?
This person is ready to be pulled out from inside. Achieving that harmony between the external and internal. Finally to just not have the physical or external define him... Its hard to surmount the external or that which defines you. But there's hope in being able to identify that there's something else or more inside and acknowledging that you're ready for it to manifest. Takes the focus away from the extremities of your life and enables you to focus on the inbetween, the diverse, and the colorful.