My entire family thinks I'm colorblind because I lied once when I was 12

When I was 12 I completely screwed up a geography assignment because I colored several countries the wrong colors. My teacher looked at it, looked at me, and asked, "Are you red-green colorblind?" I was embarrassed and instead of admitting I had grabbed the wrong markers, I said yes. That should've been the end of it. Except she mentioned it to my mom at a parent meeting. My mom came home incredibly concerned and asked why I had never told anyone. I panicked again and said I thought everybody saw colors the way I did. For some reason that answer was convincing enough that my entire family accepted it. I then spent the next decade casually maintaining a medical condition I do not have. Someone would ask what color something was and I'd squint a little before answering. If two colors were close, I'd deliberately get one wrong occasionally. My brother once defended me during an argument because someone said, "How can you not tell that's green?" and he went, "Dude, he's literally colorblind." I stood there feeling like the biggest asshole alive. The worst moment happened when I was 25. My family pooled money together and bought me one of those expensive colorblind glasses for my birthday. They took me outside. My mom had her phone recording. My dad was standing there grinning. I put the glasses on and realized I was about to have to perform a fucking miracle. So I stared at a red flower for a few seconds and went, "...wow." My mother started crying. I wanted the earth to swallow me whole. The glasses are still in my apartment. My parents occasionally ask if I use them and I say "sometimes." I'm 31 now. Nobody in my family knows. At this point I don't even know if I'm maintaining the lie anymore or protecting my mother from discovering that she once cried because her idiot son successfully identified a flower he'd already been able to see for 25 years.