Bootstrap Background color
.bg-primary
.bg-secondary
.bg-success
.bg-danger
.bg-warning
.bg-info
.bg-light
.bg-dark
.bg-body
.bg-white
.bg-transparent
Bootstrap Background Gradient
.bg-primary.bg-gradient
.bg-secondary.bg-gradient
.bg-success.bg-gradient
.bg-danger.bg-gradient
.bg-warning.bg-gradient
.bg-info.bg-gradient
.bg-light.bg-gradient
.bg-dark.bg-gradient
Bootstrap Background Color Opacity
This is default success background
This is 75% opacity success background
This is 50% opacity success background
This is 25% opacity success background
This is 10% opacity success background
Bootstrap Background Gradient Opacity
This is default danger background
This is 75% opacity danger background
This is 50% opacity danger background
This is 25% opacity danger background
This is 10% opacity danger background