@mustfacel.celik Check out this fiddle that I just created http://jsfiddle.net/Shreerang/Mvwjb/2/. Hope this helps!
You were applying the background-color to h3 which is not expected. You need to apply it to the div within.
@mustfacel.celik why do you need the styles in the markup. You can might as well handle the styles from the CSS file by having different classes/colors for your different divs. Take a look at this fiddle. What do you think?