YOU SAID:

My favorite color is navy blue, but I don't like dark blue, just navy blue

INTO JAPANESE

私の好きな色は紺色ですが、私は濃紺、紺色

BACK INTO ENGLISH

My favorite color is dark blue, but I am dark blue, dark blue

INTO JAPANESE

私の好きな色はダークブルーですが、私はダークブルー、ダークブルーです

BACK INTO ENGLISH

My favorite color is dark blue, but I am dark blue, dark blue