CSS: RGB transparency not working?

Question

I'm sure this is a stupid question but whenever I put in a value for transparency, it goes completely transparent.

.studentHelp#sidebar{
  position:fixed;
  left:-300px;
  top:30px;
  width:300px;
  height:100%;
  background-color:rgb(0,255,255,0.3); // this should be opaque?!?!?!
}

I've tried setting

'opaque: 0.3'

but then all of the child elements inherit the transparency? Any help is appreciated and thanks in advance!

Answer 1

Hey neau try using rgba and goodluck!

Answer 2

should be:

background-color:rgba(0,255,255,0.3);

note the rgb*a*