What is opacity and how to add it
Opacity refers to how much you can see through something. The code to control a part of your layouts opacity is opacity: .9;. Add it to the part of the layout code you want to affect. You can add it to any part of your list. For example, say I want to add it to this part of the code:
Just keep in mind it will make the entire area including fonts on that part more transparent as well! So if you want to affect something like the background color, see below
How to adjust the opacity of a list part
You can adjust the number to change the degree of how much you can see through it. Normally, parts of your layout are set to opacity:1; by default. This is no opacity (not see through at all). opacity: 0; is completely invisible. Even if a part of the layout is invisible, its still there and would cover up links behind it. If you want to remove a part of the layout, use display: none;
I'll play with different opacity settings on the K-on! header pic (from the K-on! layout).
opacity: 1; (default before you add opacity code)
opacity: .9;
opacity: .4;
opacity: .0;
Affecting opacity of a list's background color instead
Sometimes you'll want to change the opacity of your list so you can see the main background better behind it, but when you add opacity to your list more than you wanted will become transparent! Like in this example above.
A lot of people get that since they want to change the background color to a more transparent one but end up affecting the list's text too. You can't use the usual opacity code for that. If you want to affect only the background color on the list with opacity not the rest of the list, you need to replace the background color with RGBA color which allows you to target just the background color with opacity. For more info on it, go to this tutorial and scroll to Changing the list background color + opacity of the list background.
Control the entire list's opacity
This will let you control the entire list's opacity. This isn't including the main background of your list page. The amount of opacity determines how see-thru it is, whether its barely see-through or completely transparent.
/*LIST OPACITY
The amount of opacity (between .01 and .99) determines how see-thru it is. .01 is almost completely clear. .99 is almost completely opaque. You can choose any number between .01 and .99 to find your desired settings.
*/
.status_selected, .header_title, .category_totals, .td1, #grand_totals, #copyright,
.status_not_selected, .table_header, .td2 {
opacity: 0.99;}