Hi,
It can be done via CSS modifications only.
The CSS file you need make edit is this:
ROOT/templates/<yourjoomlatemplate>/html/com_virtuemart/assets/css/flexibleVM2Global.css
And look for this CSS rule:
.checkout-content-cart {
border-left:thin solid #a5a5a5;
border-right:thin solid #a5a5a5;
border-bottom:thin solid #a5a5a5;
padding:15px;
margin-top:-10px;
margin-bottom:10px;
background: url(../images/Flexible/checkoutBack.jpg) repeat-x #e2ddd9;
}
As you can see in this CSS rules, this element uses the checkoutBack.jpg image, and it is background has this Color: #e2ddd9
You can change the background rule to something like:
background: #ffffff;
The background of checkout page will be changed to "white".
And do the same thing in this CSS rule as well (within the same CSS file)
.checkout-content {
border-left:thin solid #a5a5a5;
border-right:thin solid #a5a5a5;
border-bottom:thin solid #a5a5a5;
padding:15px;
margin-top:-10px;
margin-bottom:10px;
background: url(../images/Flexible/checkoutBack.jpg) repeat-x #e2ddd9;
}
Which is for the "Login BOX" in the shopping cart page.
For other changes, download "Firebug" Plugin for your Mozilla Firefox (just google it), and investigate element you are willing to modify. This "firebug" plugin will show you the ELEMENT name and which CSS file contains that CSS rule and in which Line number. So you will open that CSS file, find that CSS rule and make the changes. That simple ;)
Cheers.