the color is good for me, also the layout is clean... the only thing that you need to fix are the images optimized to load the site better.. and also putting more content is advised specially in the main page.. good luck!
agree with you, don't insert css in html,. create it as tableless/full div based or css site, and also practice w3c standard, you can check your code in http://validator.w3.org/
good luck!