In order to make the display of the OLPC more visible in broad daylight, its designers decided to allow the display to shift from color to 200dpi greyscale under sunlight—both clever and cost-effective. It's great they addressed this problem now, since if there's one thing developing countries have a lot of, it's sunlight.
As you can see from the shot, the lack of color is more than made up for by the fact that you can actually use the screen, something that's posed a few problems for more than a few engineers.
OLPC 2B1 Prototype Display in the Wild! [OLPCNews]