"It is green."

Translation: Mae hi'n wyrdd.

[ChrisMSully]

mae e'n gwyrdd OK?

[EllisVaughan]

Mae e'n/o'n/hi'n wyrdd are all correct answers. You might have been marked wrong because you didn't mutate gwyrdd after yn. Yn causes a soft mutation when placed before an adjective/adverb or a noun, but a nasal mutation before a place.

[Beverley198278]

Why is mae'n wyrdd wrong?