"Ñurha kastra qintra urnen."

Translation: I see my green turtles.

[RonnieLong4]

It told me grue was the right word for the color, I'm not sure that's a thing

[Zafhira1]

It said that the right translation is green,but the word "kastra" means both blue and both green.So why the blue is not correct in the sentence?