Yes, I remember the colors of Mars being questioned during the Viking mission when compared to the craft itself, etc. The reddish dust in the atmosphere was very prominent which is why the Green in that MarsDial tab may not show it's true Green color as perceived on Earth.

if the sky is actually ochre-grey and the sun a weaker light (as seems plausible) then you SHOULDN'T match the colours of the tabs.

True!

Try playing with coloured lightbulbs or filters and a coloured target - you'll see what I mean. In the extreme, you can't tell some colours apart.

Unfortunately in my line of work, I can't do that. I paint with lots of colors under the most natural light possible. If I work at night I only use flourescent bulbs. *g*

I forgot about the weaker sunlight (in conjunction with the dust/fines and even water molecules in the atmosphere....).

The color Blue on Mars may show as having a hint of Purple.