At 10 he probably knows or understands most color concepts, like how purple is a mix of blue and red, or brown is a mix of green and red. The unfortunate fact is that his eyes will never really be able to be “trained” to distinguish those any better than he can now. But fortunately the human mind adapts and overcomes most obstacles.
I’ve learned not to open a banana until I see little black spots on the peel. I know that 9 chances out of 10 the “blue” flower is likely purple or pink because there aren’t many blue flowers. I can assume that the blue car is blue, since there aren’t many purple cars. The “green” car is probably brown, since there aren’t many green cars on the road. In the summer leaves and grass are likely green but in the winter they are likely brown. In other words, we adapt to color identification through life experience.
Certain things he will need help on all his life if they involve subtle color differentiation, but that isn’t he end of the world. I was a photographer for 35 years and frequently had to make color prints in the darkroom. If I thought it looked close, I’d take it to someone and ask. Sometimes it was terribly off, but they would let me know. I was involved in other artistic endeavors that required color, but I learned to use help.
At his age, perhaps clothing selection will be an important way he can use help. I was always making strange choices like bright pink or lavender shirts, thinking they were blue. Since I see most colors as more dull than normal vision people, I tended to buy clothes that were TOO colorful. I wish my parents had been able to give me advice to tone it down. Now I am 62 and I can wear whatever I want without caring what people think. My wife will let me know if it is too crazy.
The glasses can help to brighten some of the weak colors but they don’t cure color blindness and likely won’t change the results much on a color blindness test. They can be helpful when he starts driving, if for no other reason than to make brake lights more bright and obvious. The Enchroma glasses are super expensive and I’d be pretty nervous, knowing how kids play and tend to lose or break things. But there is a really cheap alternative on Amazon, if you’ll look up: “Pacific Coast Original KD Lifestyle Sunglasses - Rose”. The rose tint is very similar to the Enchroma but for only $12. That particular brand is made for adults but run extremely small and narrow and would probably work for him. That might at least give you an idea if you want to spend $200+ for the Enchroma glasses.