Explanation:
Starting with the image in paint, the trees. They clearly have a white grid of pixels (i.e. every other pixel appears to be white).
In actual fact, these 'white' pixels are coloured pixels with a maximum value and very low saturation (using the HSV model), meaning they are coloured but have maximum brightness so appear white.
Decreasing the saturation and value of all pixels causes the 'white' ones to become visible (coloured) and the originally coloured ones become black.
Why browsers display the pixels differently to other applications, im not sure, but that's the explanation of how, just not the why.
