RGBA stands for Red Green Blue Alpha. It is an extension of CSS2, Alpha specifies the opacity of a color and parameter number is numerical between 0.0 to 1.0.
Example
The following example shows rgba color property −
<html> <head> <style> #p1 {background-color:rgba(255,0,0,0.3);} #p2 {background-color:rgba(0,255,0,0.3);} #p3 {background-color:rgba(0,0,255,0.3);} </style> </head> <body> <p>RGBA colors:</p> <p id = "p1">Red</p> <p id = "p2">Green</p> <p id = "p3">Blue</p> </body> </html>