Color de fondo de opacidad CSS
background: rgba(255, 255, 255, 0.25);
Lucas Juan
background: rgba(255, 255, 255, 0.25);background-color: #ff000088; <--- the 88 is the alpha
background-color: #ff0000 50%;.opacity30 {
opacity: 0.3;
filter: alpha(opacity=30); /* For IE8 and earlier */
}/* css semi-transparent background color */
.bg-semi-transparent {
background-color: #ffffff40!important;
/* change numbers from 00 to 99 at last of hex code
for transpency you want. */
}h1 {background-color:rgba(255,0,0,0.3);}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 */