A new trick available in css3 is to allow you to alter the transparency of a divs background colour without it affecting the text/image inside it.
This is done using the RGBA style.
Basically you add the colour in RGB format and at the end add the opacity/transparency of the colour.
The css rule will look similar to below, this is the one used for the background to our slider used on our site ClassicDomains.co.uk – Take a look.
border: 2px solid #fff;
The first part being the rgb (192,209,125) for our hex colour and
the latter part of the number (0.4) being the opacity.
You can find a hex to RGB converter here.