change opacity inside of a section html code example

Example 1: background color opacity

rgba(51, 170, 51, .1)    /*  10% opaque green */ 
rgba(51, 170, 51, .4)    /*  40% opaque green */ 
rgba(51, 170, 51, .7)    /*  70% opaque green */ 
rgba(51, 170, 51,  1)    /* full opaque green */

Example 2: container transparent text opaque

.mycontainer {
    background: rgb(60, 60, 60);
    background: rgba(60, 60, 60, 0.4);
}

.mycontainer a {
    color: #fff;
}