“Bugger this. I want a better world.”
"Do not offend the Chair Leg of Truth; it is wise and terrible."
I don't understand why the cards need that icon though. The basic action already shows the coal option. It makes more sense to my group that you're simply appending the card bonus to the regular action. There just doesn't seem to be any sense in reminding the player that they have a one coal option on the cards itself. If those cards had the "correct" icons on them, there's be no need for any additional explanations for either card.
That's absolutely right and the icon on the train and contract should be only 2-colors.
Overall, you will be able to take 4 cubes, only one of which can be coal. If you unify that, the iconography would be: +++ (where 2 is 2 color, and 3 has the coal 3rdd color). ++ is already part of action A, what's missing is , not . Right now, if you consolidate the cards as they are, you get +++. That allows for 2 coals and we played it that way until now,
Seriously, no one will ever call out "you took 3 iron first, you can't take a coal as your 4th because the train doesn't have the coal symbol". It's obvious that you could have taken one coal as part of your first 3 cubes and that you can then make your 4th a coal if you haven't taken one yet. Just like you won't blame someone for taking 1coal + 2 iron instead of 2 irons + 1 coal for action A. Seriously, that's not a justification for faulty iconography.