Change background color oo Post

If you are wishing to change the back ground color of your post in blogspot, log into your count-->layout-->edit html and expand click on expant widget template and search for the following code;
.post {
margin:.5em 0 1.5em;
border-bottom:1px dotted $bordercolor;
padding-bottom:1.5em;
}
you may try by adding the code <-background-color: #000000-> as a start(you can choose variouse colors from the hex code chart)
so it will look like this
.post {
margin:.5em 0 1.5em;
background-color: red;
border-bottom:1px dotted $bordercolor;
padding-bottom:1.5em;
background-color: #000000

If youy rather want to change the whole color behind the post title and post itself, the look for the following code

#main-wrapper {
width: 580px;
padding: 10px 10px 10px 10px;
margin-left: 75px;
margin-right: 0px;
border:4px dashed $bordercolor;
float: $startSide;
word-wrap: break-word; /* fix for long text breaking sidebar float in IE */
overflow: hidden; /* fix for long non-text content breaking IE sidebar float */
}
}
and add the same code or just go to the chart and search for your desired color
background-color: #000000

so it looks like this
#main-wrapper {
width: 580px;
padding: 10px 10px 10px 10px;
background-color: red;
margin-left: 75px;
margin-right: 0px;
border:4px dashed $bordercolor;
float: $startSide;
word-wrap: break-word; /* fix for long text breaking sidebar float in IE */
overflow: hidden; /* fix for long non-text content breaking IE sidebar float */
}

wish you a happy blogging. any question just leave a comment and i will get back to you.