Cross browser rgba transparent background while keeping content (text & images) non-transparent

Question

I want to get rgba backgrounds working with all browsers. I did some searching and found out that generally there are three types of browsers out there:

1) Browsers

Answer 1

I think browsers which don't support rgba don't support base64 neither. However you can simply use a 2x2 px semi-transparent png background image (not 1x1 to avoid a weird bug with IE).