Clearing obstacles

[Liebchen]

If the letters are in orange, the unit is capable of performing the action but not eligible to do so in its current state.

I couldn't find the distinction in the manual either, and it's not entirely clear why the distinction is made. Perhaps it's intended to offer a visual clue that the unit needs to, for example, switch to Deployed state. Or that the reason the unit didn't suffer losses when entering a minefield was due to it being an Engineer-type unit.

I will frequently move deployed engineers into a RUBBLEd hex and use the "engineer" menu to command them to clear rubble, just so that they'll be preset next turn. When I do that, the words "clearing rubble" are orange.