Some Sony Xperia S units have a faulty display, Sony addresses the issue

There is a whole lot to love about the Sony Xperia S: it has a gorgeous display, snappy camera, and a catchy design. (More on that in our Sony Xperia S Review.) However, it is not entirely free of glitches, as some users are now finding out.
The display on a few Sony Xperia S units exhibits a yellow tint under certain conditions, and many unlucky users who have purchased a faulty unit are now reaching out to the interwebs for a solution. Fortunately, an official response from Sony has already been posted. It goes as follows:
Sony Mobile Communications has identified that the display on a limited number of Xperia S smartphones may show a slight yellow tint if exposed to temperatures above 40 degrees Celsius. This is limited to a small number of units and the cause of this has been corrected. Any consumer observing this slight yellow tint on the display of their Xperia S is welcome to contact their local customer service centre and Sony Mobile Communications will resolve this at no cost to the consumer.