So, along with a lot of other people I did a win/loss matrix, and I find a different answer from anyone else's. By my calculation, Yellow Sword / Green Armour strictly dominates.

Under the given hypothesis of very large HP, the winner of a duel is simply the one that does most expected damage per minute; the formula is (damage-reduction)(speed(1-dodge)).

I think rosyatrandom's table must be wrong. He says that B/B beats B/G, which is false; consequently there must be a mistake in his calculation. Consider: The blue sword does 100x80x0.76=6080 damage to the green armour, and 88x80x0.9=6336 damage to the blue armour; consequently blue sword and green armour beats blue sword and blue armour.

Edit: Never mind, I made a mistake in my script. Back to the drawing board until I find the bug.

Edit2: I'd put in the wrong speed values for the yellow and green swords. Now I don't find a dominant strategy.