This is because the image has been (IR) since this cuts out cloud & fog
to give clearer detail. VIS is also black n White but will detail clouds & fog which may obscure the entire zone or most of it.
Then later these images are built up into colour, giving you the more
natural look and any info missing in the subject.
If you check regions like the Himalayas India, Nepal, Tibet you'll come across this effect were some arrears are in B/W and others are colour.