my dad has blue eyes, my mom has green,my brother has blue and my other brother green. I have brown?

Of course it's possible.

People who have brown eyes are considered attractive, confident and adorable. They are independent people who love to make new friends, are polite and caring. They can cheer people up and make them laugh. They have an affectionate nature and care very much about their family. They are self-confident and very determined, persevering people. They are nature lovers, spiritual, and can be very strong headed at times.

For more on personality traits of eye color follow the learner365 link below.

Your adopted! Na joking it is possible because the brown eye gene is more dominant it ha effected you from you grandad and the others just had 2 sets of blue/green gene crossed you probably had brown with another e.g green/blue

Yes of course it's possible, my parents both have dark hair and hazel eyes, one of my sisters has black hair and green eyes, I have brown hair and hazel eyes and my sister has blonde hair and blue eyes, we all have the same parents.

You got the gene that was recessive in your parents.