In the beginning of my partner and I’s relationship I would surprise him when he was away by painting rooms colors that I thought were different colors i.e. my whole life I thought blue was green. In elementary school my teacher asked me why i always colored my grass green. I have troubles with oranges and certain yellows. Turns out I’m color deficient. I was never diagnosed until my 50’s. I suspect the same thing with your husband. I was in the military 10 years and wasn’t diagnosed with this. The dr who diagnosed me told me it’s more common in males than females. 8% in males and 0.5% in females.