changing good ol kubrick background colors

OK Guys,
I got my personal header in…..
I understand the default background is a jpg file.
I know it needs to be changed in the themes.php
I am looking at the following:

body { background: url(“<?php bloginfo(‘stylesheet_directory’); ?>/images/darkblue.jpg”); }
<?php /* Checks to see whether it needs a sidebar or not */ if ((! $withcomments) && (! is_single())) { ?>
#page { background: url(“<?php bloginfo(‘stylesheet_directory’); ?>/images/kubrickbg.jpg”) repeat-y top; border: none; }
<?php } else { // No sidebar ?>
#page { background: url(“<?php bloginfo(‘stylesheet_directory’); ?>/images/kubrickwide.jpg”) repeat-y top; border: none; }
<?php } ?>
#header { background: url(“<?php bloginfo(‘stylesheet_directory’); ?>/images/personalheader.jpg”) no-repeat bottom center; }
#footer { background: url(“<?php bloginfo(‘stylesheet_directory’); ?>/images/kubrickfooter.jpg”) no-repeat bottom; border: none;}

I changed the first Kubrick reference with a small dark blue image file and it gave me a shadow around the blog body. Not what I thought it would do, but I liked it and left it.

Question 1. Do I only need to replace the (kubrick/bg/wide/footer) references with a color.jpg?
Is that it? Nothing else on the sheet? No messing with the style.css?

Question 2. If I create a color.jpg and upload it to my images directory, what size (pixels x pixels) does it need to be? Does it matter? I understand it repeats.

Just an analog idiot here. I’m trying to do this without messing anything up and learning as I go.

thanks in advance for any help,
Stikguy

https://www.stiknstein.com/