I think they might be. blue would've been a better choice. it's weird that people still use red and green when it's the best known and most common form of color blindness and it affects as much as 1 in 20 people, give or take. that's not a small percentage. color blindness in general affects 1 in 12 people.
that's for red-green, which is why I said about 1 in 20 -- maybe closer to 1 in 25 -- but in total, all color vision deficiency types add up to around 1 in 12 people.