css rgba explained code example
Example 1: rgba red color
rgb(255,0,0) /*red*/ Hex #FF0000
Example 2: background color cs rgba
#p1 {background-color:rgba(255,0,0,0.3);}
rgb(255,0,0) /*red*/ Hex #FF0000
#p1 {background-color:rgba(255,0,0,0.3);}