Can someone check my Japanese? 10 points?

Question:

My brother's hair was black but is now brown - いとうとう　は　くろかった　が　いま　ちゃいろ　です。
I am taller and smarter than my brother - わたしは　いとうとう　より　せがたかくて、　あたまがいい　です。How would you say, "I have brown hair, BUT now I have black hair"

I know I made a lot of grammatical errors:( It's just so hard at the moment and the grammar is confusing me, so don't kill me for it :)

Answer:

おとうと　の　かみ　は　くろかった　が　いま　は　ちゃいろ　です。
My little borther's hair was black, but it is now brown.

わたし　は　おとうと　より　せ　が　たかくて、　あたま　も　いい　です。
I am taller than my little brother, and aslo smarter.

わたし　の　かみ　は　ちゃいろ　だった　が、　いま　は　くろい　です。
My hair was brown, but now it is black.　

in japanese, we normally say my hair is black, rather than i have black hair.