Changing background color

You will need to do some css editing… But it is really simple.
you would also need to change the font color to white – to be able to read…

add the following:

.entry-header, .entry-content,content-area {
background-color: #000 !important;
color: #fff;
}

thanks a lot..do I just add it or is there a line number i have to insert the code?

You can just edit it to the stylesheet – but if you want to preserve the structure and make it future proof, you should comment the block and insert it in the part of the stylesheet that deals with the style of the content.

Any way, it will work even at the top part of the stylesheet.

It’s really not a good idea to modify any theme files – as those changes will be lost when WP is updated. It’s also inadvisable to modify a default theme as you may need it for troubleshooting.

You can safely make changes using a child theme or custom CSS plugin.