Learn Danish: Den grønne nuance er en farvemæssig succes. - The green shade is a color-wise success.

The suffix -mæssig translates roughly to '-wise', 'in terms of', or 'regarding'. By adding it to the noun farve (color), it creates an adjective meaning 'in terms of color'. So, a farvemæssig succes is a success specifically regarding its color.

Could I use the other productive suffix from this lesson and say farveagtig succes instead?

No, because -agtig means '-like' or 'resembling' (similar to '-ish' or '-y' in English). Farveagtig would mean something looks 'color-like', which does not make sense here. You want to state the shade is successful in terms of its color, which strictly requires -mæssig.

Why does farvemæssig not have an -e ending here, even though grønne does?

Adjectives ending in -mæssig follow standard adjective agreement rules. Here, it modifies the indefinite, common-gender noun en succes, so the adjective takes no ending. Grønne takes an -e because it is part of a definite noun phrase (Den grønne nuance), which forces the adjective into its definite form.

Why is there a double 'n' in grønne when the base word is grøn?

When you add a vowel ending (like the definite -e) to a word ending in a single consonant preceded by a short vowel, the consonant doubles. This spelling rule ensures the ø sound stays short. If it were spelled with only one 'n', the vowel would be pronounced as a long vowel.