This is a function of how photographic scenery works. The aerial photographs that go to make up the scenery are usually taken between March and September because this is the time of year when aircraft can fly most often and the weather conditions allow photographs to be taken. As a result, when large numbers of images are put together to form areas of scenery you can occasionally see seasonal variations between areas taken at different times of the year. This shows up as a slight change in the general colour of the landscape between one area and another. One way round this is to ‘correct’ all the colours artificially. Unfortunately, this can lead to some very unrealistic hues in the landscape – blue/grey fields and purple rocks! For this reason we have kept the correction levels to an absolute minimum. The trade-off for this is some seasonal variations, but we think that these very occasional changes are preferable to an overall ‘unrealistic’ set of colours.