With the masculine adjective, I thought that red describes some noun. That's why I answered "...the red one."
I thought the same -- it's an adjective, thus implying a noun, rather than meaning "I don't like (the colour) red"
probably because the word for color is masculine: Красный цвет. This exercise seems to be talking about the color itself. However if you use the feminine or neuter, Я не люблю красную/красное, then you are most likely referring to some feminine or neuter noun that happens to be red. For example,
-Я люблю эти машины. -Я не люблю красную.
-"I like these cars." -"I don't like the red one."
Why not "Я не люблю красного."? (My logic is - in Polish we'd say "Nie lubię (koloru) czerwonego.", so it's in the Genitive case.)
In Russian, "Не люблю красный (цвет)." Because the accusative animate "красного," implies that I don't like the red person, red animal, red fruit/vegetable, etc. The accusative inanimate case is "красный." Plus, it's masculine because "красный цвет" is a masculine noun.