You could do it with a custom container skin:

Create a copy of a container skin, name it something else, add CssClass="my_ew_title_class" attribute to the TITLE tag. Eg:

<dnn:TITLE runat="server" id="dnnTITLE" CssClass="my_ew_title_class" />

Define my_ew_title_class in container.css. Then go into SETTINGS for your blog module PAGE SETTINGS -> MODULE CONTAINER and select the container you made.

You could reference the unique moduleID and change the title it with a quick line of css, however i dont like hardcoding things like this becuase if you remove the module and add it again so the ID changes then you'll have to keep going back to your CSS and changing the reference.

You can find the id by viewing the source code of the page.

#dnn_ctr375_dnnTITLE_lblTitle { background-color:#FF0000; }