Forget blue and brown leather.

What you really need is a chrome bottle cage - which matches the stem, the drivetrain components and the seatpost - and a white seat to match the handle bar tape and brake hoods.

My opinion is that these sorts of colours look acceptable on bmx bikes - but not on classic road bikes. I like to minimise the use of different colours - and also match colours evenly accross the bike.

A very nice and clean looking bike anyhow - so I suppose you can choose what you like.