No; they just distinguish between fewer basic colours than English speakers do.
Stereotypically, English-speaking men have fewer colour terms than women, not using words such as “chartreuse” or “lilac” or “peach” — not because they are incapable of seeing colour or of distinguishing shades, but because they do not consider such fine distinctions relevant.
Klingon is similar; the basic colour terms are just two: Doq for “warm” colours (red, orange, brown) and SuD for “cool” colours (yellow, blue, green). Plus chIS “white” and qIj “black” which are not colours per se.
It’s not that they can’t tell the difference between green and blue, but it’s more like how many men see no point in distinguishing between “teal” and “cyan” if “blue” will do,.
Some of the color terminology is confusing and inconsistent. I think that mostly we've tried to stay consistent with canon usage. I think both of those terms have been used for Brown in canon. The following link is for the best summary I've seen of Klingon color terms: http://klingonska.org/ref/color.html