Translation:The roofs have a very beautiful color here in Denmark.
'Rooves' should be accepted. Even though 'roofs' is considered standard, 'rooves' is still used:
'Apparently both roofs and rooves are still in use, therefore both are correct even if one form is used more than another." - https://english.stackexchange.com/questions/13183/plural-of-roof (you'll find several references in the positive for 'rooves' there).
I believe it depends on where you were raised and is a dialect thing. I grew up on Long Island and use 'rooves'.
very = meget = sehr
a very beautiful colour
en meget smuk farve
eine sehr schöne Farbe
pretty = ret = ziemlich
a pretty beautiful colour
en ret smuk farve
eine ziemlich schöne Farbe
On the note of the u in colour not being accepted, sometimes if you get an answer wrong and "colour" isn't specifically written in the incubator, it regards it as a typo (and therefore crosses out the word as though it is wrong), but if you get it right, it will not give a typo message and just suggest the spelling used in the incubator as an alternate translation