Masters Edition III

Call to Arms

As Call to Arms enters the battlefield, choose a color and an opponent.
White creatures get +1/+1.
When the chosen color isn't the most common color among permanents the chosen player controls, sacrifice Call to Arms.

As this enchantment enters, choose a color and an opponent.
White creatures get +1/+1 as long as the chosen color is the most common color among nontoken permanents the chosen player controls but isn't tied for most common.
When the chosen color isn't the most common color among nontoken permanents the chosen player controls or is tied for most common, sacrifice this enchantment.

Ice Age

Choose a color. As long as target opponent controls more cards of that color than any other color, all white creatures get +1/+1. If at any time that opponent does not control more cards of that color than any other color, bury Call to Arms.