White text on Black background on iMac
Not too long ago I was developing a website for a client that uses a black background with white text. I noticed the white text appearing rather bold so I assumed my CSS was faulty and somewhere was a font-weight set to bold. The fact that this was only happening in all browsers on the Mac platform should have been a pointer to the issue. However, as always I question my code first but after intensive research on the CSS it turned out it had nothing to do with the code at all.
After Googling on it for a bit, the only article I found discussing this issue was by Jason Patterson on this lengthy forum topic. The forum discusses Mac OS X’s sub-pixel AA and Patterson takes the opportunity to claim there’s a bug in Mac OS X’s sub-pixel AA rendering for white/light text on black/dark backgrounds.
He also did a thorough test which you can see here.
I created my own tests, one html file for those who want to check if they experience the same issue and one screenshot of how it looked like before I changed my iMac’s default font smoothing style setting.