Default CSS Styling

Im sure that this question has been asked many times in the past and i did do a search on here before i posted this but couldnt find it.

My website http://blog.housejak.com i have the default theme on however i want to edit the text colours etc but when i go into the CSS i cannot see where to edit at all.

Please bare with me as im new to WP.

Thanks in advance,
Dom