If you need to get support into older browsers that don’t support RGBA like Firefox 2 and below, you may be able to use canvas to emulate the effect. Firefox 2 doesn’t support rgba in CSS, but it does in canvas. You can generate a one pixel image with canvas, and set it as a background using data urls. While this might not sound like a very well performing solution, and certainly doesn’t work when javascript is disabled or the browser doesn’t have canvas support, it is a good solution for development. Once you put a site into production, you can embed the generated data url right into your css.
Devon Govett
If you need to get support into older browsers that don’t support RGBA like Firefox 2 and below, you may be able to use canvas to emulate the effect. Firefox 2 doesn’t support rgba in CSS, but it does in canvas. You can generate a one pixel image with canvas, and set it as a background using data urls. While this might not sound like a very well performing solution, and certainly doesn’t work when javascript is disabled or the browser doesn’t have canvas support, it is a good solution for development. Once you put a site into production, you can embed the generated data url right into your css.