Setting a background for MMM-NOAA3

[wheresmygravy]

Very new to CSS and I am wanting to add a translucent background to a module.

My MagicMirror is not actually a mirror at all and will be mounted in the kitchen. I am using MMM-BackgroundSlideshow to display images to the screen under the modules. The only problem is seeing the modules on top of random images is sometimes difficult. So I would like to place a translucent charcoal behind the modules so I can see them better.

For my calendar I am using MMM-CalendarExt and it does that automatically. I want the same kind of thing behind the MMM-NOAA3 module. I am sure it will be in the custom CSS for MMM-NOAA3, just not sure of the exact location.

Thanks for your help in advance.

Here is the contents of MMM-NOAA1.css file:

@import url('https://fonts.googleapis.com/css?family=Muli');
.MMM-NOAA3 {
     width: 195px;
}
 .MMM-NOAA3 .table th, tr, td{
     text-align:center;
     table-layout:fixed;
}
 .MMM-NOAA3 tr {
     height: 29px;
}
 .MMM-NOAA3 th {
     line-height: 20%;
     padding-top: 9px;
}
.MMM-NOAA3 .awarn {display: block; line-height: 1.3;}
.MMM-NOAA3 .blink_tr {
  animation: blinker 2s linear infinite;
}
@keyframes blinker {  
  60% { opacity: 0; }
}
.MMM-NOAA3 .img { width: 23px; height: 23px; align-content: center; padding-bottom:25%;}
.MMM-NOAA3 .moon { width: 23px; height: 23px; align-content: center;}
.MMM-NOAA3 .uv { -webkit-filter: invert(100%); width: 40px; height: 40px; padding-left: 10px;}
.MMM-NOAA3 .icon {width: 30px; height: 30px;}
.MMM-NOAA3 .aqi {font-size: .6em; color: white; text-shadow: 1px 1px 2px blue, 0 0 25px white, 0 0 5px yellow;}
.MMM-NOAA3 .windy {width: 25px; height:25px; align-content: center;}
.MMM-NOAA3 .wheading {
     background-color: #b97e11;
     text-align:center;
     color: rgba(0,0,0,0.6);
     text-shadow: 2px 8px 6px rgba(0,0,0,0.2), 0px -5px 35px rgba(255,255,255,0.3);
     padding: 2px;
     font-size: 14px;
     line-height: 120%;
     border-radius: 5px;
}
 .MMM-NOAA3 .Forecasttable {
     float: left;
     clear: left;
     display: inline;
     margin-left: auto;
     margin-right:auto;
     text-align: center;
}
 .MMM-NOAA3 .rheading {
     background-color:  #cc7a00;
     text-align:center;
     color: white;
     text-shadow: 2px 8px 6px rgba(0,0,0,0.2), 0px -5px 35px rgba(255,255,255,0.3);
     padding: 2px;
     font-size: 14px;
     line-height: 110%; 
	 border: 1px solid #ffe0b3;
    padding: 3px;
} 
 .MMM-NOAA3 .font {
     font-size: 23px;
}
.MMM-NOAA3 .fontac {
     color:#e4ab5f 
}
.MMM-NOAA3 .fontss{
     color: #e0e29a;
}
.MMM-NOAA3 .fontauw{
     color:#51c7ca 
}
.MMM-NOAA3 .fontfor {
     color: #000;
}
.MMM-NOAA3 .IMG {
	width: 25px;
	height: 24px;
}
.MMM-NOAA3 .image {width: 250%;
height: 250%;}
 .MMM-NOAA3 .xxsmall {
     font-size: 10px;
     color:orange;
     margin: 10px;
	 font-family: 'Muli', sans-serif;
}
.MMM-NOAA3 .tempf {
	color: white;
	text-shadow: 1px 1px 2px black, 0 0 25px blue, 0 0 5px darkblue;
    z-index: 1;
}
.MMM-NOAA3 .floatl {float: left;}
.MMM-NOAA3 .forec {
	position: relative;
    z-index: 1;
}
.MMM-NOAA3 .collapsible {
    background-color: #777;
    color: white;
    cursor: pointer;
    padding: 18px;
    width: 100%;
    border: none;
    text-align: left;
    outline: none;
    font-size: 15px;
}
.MMM-NOAA3 .active, .collapsible:hover {
    background-color: #555;
}
.MMM-NOAA3 .content {
    padding: 0 18px;
    display: none;
    overflow: hidden;
    background-color: #f1f1f1;
}
.MMM-NOAA3 .index{
  position:relative;
  z-index: 1;
}
.MMM-NOAA3 .dates {font-size: 12px;}
.MMM-NOAA3  .tooltip {
    position: relative;
    display: inline-block;
	float: left;
}
.MMM-NOAA3 .tooltip .tooltiptext {
    visibility: hidden;
	width: 200px;
	font-size: 17px;
    background-color: black;
    color: #fff;
    text-align: center;
    border-radius: 4px;
	border-style:solid;
    border-width:1px;
    border-color:white;
    transform: translate(-50%, -50%);
	box-shadow: 0px 0px 0px 2px #888888;
	​padding-top: 3px;
    padding-right: 5px;
    padding-bottom: 3px;
    padding-left: 5px;
	line-height: 20px;

    /* Position the tooltip */
    position: absolute;
    z-index: 1;
}
.MMM-NOAA3 .tooltip:hover .tooltiptext {
    visibility: visible;
}

.MMM-NOAA3 .CellWithComment{
  position:relative;
  z-index: 1;
}
.MMM-NOAA3 .CellComment{
  width: 80px;
  line-height: 14px;
  display:none;
  float: center;
  box-shadow: 0px 0px 0px 2px #888888;
  height: auto;
  z-index:100;
  background-color:#080808;
  border-style:solid;
  border-width:1px;
  border-color:white;
  padding: 10px 5px 10px 5px;
  font-size: 12px;
  color:white; 
  position: absolute; right: 0; bottom: 0; 
  bottom: 15px;
  text-align: center;
  border-radius: 5px;
}
.MMM-NOAA3 .CellComment2{
  width: 100%
  line-height: 14px;
  display:none;
  float: center;
  box-shadow: 0px 0px 0px 2px #888888;
  height: auto;
  z-index:100;
  background-color:#080808;
  border-style:solid;
  border-width:1px;
  border-color:white;
  padding: 10px 5px 10px 5px;
  font-size: 12px;
  color:white; 
  position: absolute; right: 0; bottom: 0; 
  bottom: 15px;
  text-align: center;
  border-radius: 5px;
}
.MMM-NOAA3 .CellWithComment:hover span.CellComment{
  display:block;
}


 
.MMM-NOAA3 .divTableParent{
        max-height: 20px;
        overflow: auto;
        overflow-x: hidden;
    }
 .MMM-NOAA3    .divTable { 
        display: table;
		line-height: 8px;
        width: 100%;
        font-size: 14px;
		text-align: center;
		color: white;
    }
 .MMM-NOAA3    .divTableBody {
        display: table-row-group;
    }
.MMM-NOAA3     .divTableRow {
        display: table-row;
        position: relative;
		line-height: 20px;
    }
.MMM-NOAA3     .divTableHead {
        line-height: 5px;
        color: #ffe0b3;
        border-right: 1px solid rgb(0, 0, 0);
		line-height: 2px;
        font-weight: 700;
    }
 .MMM-NOAA3    .divTableCell, .divTableHead {
        border: 1px solid rgba(44, 46, 46, 0.15);
        display: table-cell;
        padding: 8px;
		height: 3px;
		width: 33%;
    }
.MMM-NOAA3 	.divTableCell2 {
        display: table-cell;
        padding-bottom: 30px;
		float: left;
		font-size: 72px;
    }
 .MMM-NOAA3    .divTableCell, .divTableHead {
        border-bottom: 0px;
        border-right: 0px;
    }

[wheresmygravy]

Also, is it possible to add an OPACITY setting to the background?