First one in mind is a strong blue overdyed with black called "His first name is 'Agent'."

Love it!

Red and gold for Iron man, red overdyed with black for Black Widow, green/black/gold for Loki...

Loki's could be called "Puny god".

Oh, and "Genius, playboy, billionaire, philanthropist" for Tony.

Ooooh, or for Tony, the place where I've ordered yarn blanks has a blend w/gold-toned metallic in it.

Good for Loki too.

We could use one of the skeins as a prize.