change the style

Hello,
The block titles style is added by the demo you install .the default demo has these title tags: http://demo.tagdiv.com/newspaper/
If you want another style, you can pick another demo. pick one from the list on the right to see how it displays.
For your second question,
The color of the titles can be selected from here: http://screencast.com/t/m5dnpOFAbC
The category tag and the comments can only be targeted with css as there is no color setting for them. Try this code:
.td-post-category, .td-big-grid-meta .td-post-category, .td-module-comments a{
background-color:red;
}
Thanks.