Here is some ideas of new tokens (so to put on tasks):
1a) fire token: tasks with fire must be done back to back
These tasks is only a small drawback since it's fairly easy, but sometimes, if the player who got the first one can't play the second color, it's bad. So he will want to do the other one first, so he could comm. Enjoy

There can be more than 2 fire, but then, the middle fire will not be able to win two tasks in one trick

(except if both has fire)
1b) ice token: same than fire
You can mix fire and ice. You could imagine a mission with 4x Fire, and 4x Ice. This means, you really would want to communicate to know which series of 4 you do first.
2) discharge token: the player who chose that task lose their communication
Simple, effecient.
You want to comm and want that g5? How sad

Don't take g5.
3) waiting token: the player who won the first trick take that task (the task can't be done during the first turn)
You want that g9? Np, just communicate you have y9 and want to win first trick. Oh there is a '1' task too on your mission? How sad
4) radio token: once that task is done, the player who hold this task must communicate (for free)
If he has only rockets, he show nothing.
5a) dual token: when revealed, reveal two tasks instead. The player must do one of those two (and only one)
Really easy, except you don't know which task the player want to do without comm.
It reduce drastiquely the difficulty of the mission since you can keep it for the last player (or not), so use it on hard missions.
5b) duo token: when revealed, reveal two tasks instead. The player who take this task must win both
This one is more tricky, but you can often find a player who can win any task so...
5c) choice token: when revealed, reveal two tasks instead. The commander choose which task he wants in the middle.
5d) negative token: when revealed, reveal 5 tasks instead. The player who choose that task must NOT win any of them.