If a baby is born with dark blue eyes and they start changing to lighter does that mean he have brown eyes?

Not necessarily. While it is common for babies to be born with dark blue eyes that lighten over time, this does not always mean that the eyes will eventually turn brown. Some babies' eyes will lighten to a shade of green or hazel, while others' may remain blue or even turn darker with age. The final color of a person's eyes is determined by the amount and type of melanin in the iris, and this can be influenced by a number of factors, including genetics, age, and sun exposure.