Note: If you're using other templates then see this tutorial:
Blogspot How To: Change Post Title Color in Blogger-Blogspot Template Designer Templates
How To Change Post Title Color in Picture Window Blogspot Template
Posted by Bilal Aslam
By default, there is no option to change post title color in Blogger Designer Templates. I've already written a tutorial to do that but users of Picture Window template are having problems. Here is a tutorial to change post title color in Picture Window template.