Rather than try to correct the composite picture, better to go back to the original components and reassemble the image in RGB. Note that the images are taken at different times, so there is always some colour banding, but this does seem extreme. OTOH, if you look at other places on the Lander deck, you see gross colour errors in other places too.

It is possible that they skimped some colour frames that "duplicated" parts of the deck and inserted an "average" colour based on the other filters.

Matching colours is tricky on Mars, not least because the basic assumption of the sky being blue and the sun being the same yellow as on earth is not true. If a human were there, you'd get used to it and correct automatically (like wearing coloured sunglasses or swim goggles) but with a camera we get rendering of numerical values of colour, rather than subjective impressions, and when you view those onscreen sometimes they look odd indeed.

Go checkoutr Don Davis' website for lots of insightful views of Mars in "colour".

And for now, hold back on the conspiracy theories - those poor guys running the show are overwhelmed with conflicting calls on their time while we have all day to play with what takes our fancy!