Everyone knows the moon is grey... isn't it?
Well actually it isn't, it has areas with very subtle green, blue and orange tones, but these are difficult to make out with the unaided eye, though telescope users who know what they are looking for can detect them. In fact we are so used to a colourless moon, most photographs of it are rendered in monochrome.
Very careful processing of the colour balance of a photograph of the moon can make sure that none of these colours 'wins' over the others. this then allows the saturation of the image to be increased enough to make them visible. Once this colour enhanced image is combined with the 'luminosity' detail in a sharpened and carefully contrast adjusted image you can see the moon as you may never have seen it before. And this is no artefact - different photographers get the same colours in the same areas. The different colours actually reflect the age of different parts of the moon, with the younger maria (seas) being most colourful.
If you want to see the colours for yourself, the most obvious patch is the yellow/orange area near 10:30 and in a way from the rim - near the bright crater Aristarchus.
It's a bit of a wow moment when you realise the Moon is colourful... right click and 'view image' to see it in all its glory.
