Tamiyo, Field Researcher

Oracle Text
+1: Choose up to two target creatures. Until your next turn, whenever either of those creatures deals combat damage, you draw a card.
−2: Tap up to two target nonland permanents. They don't untap during their controller's next untap step.
−7: Draw three cards. You get an emblem with "You may cast spells from your hand without paying their mana costs."
Card Rulings
7/13/2016 Tamiyo’s first ability can target creatures you don’t control. You’ll draw a card, not their controller, if they deal combat damage.
7/13/2016 Tamiyo’s first ability sets up a delayed triggered ability that triggers even if Tamiyo has left the battlefield before those creatures deal combat damage.
7/13/2016 You must follow the normal timing permissions and restrictions of each nonland card you cast once you get Tamiyo’s emblem.
7/13/2016 If you cast a card “without paying its mana cost,” you can’t pay any alternative costs such as emerge costs. You can pay additional costs such as escalate costs. If the card has mandatory additional costs, you must pay those.
7/13/2016 If the card has in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.
7/13/2016 You may still cast nonland cards by paying their mana costs as normal.
8/23/2016 If Tamiyo’s first ability targets two creatures, and both deal combat damage at the same time, the delayed triggered ability triggers twice.
While those are excellent examples of white cards that permanently deal with creatures those kinds of cards are relatively rarely printed in white. Because they boarder on being outside of Whites abilities your examples boarder on black's part of the pie. White also does temporary determent, for example enchantments that only 'remove' so long as they are on the field, Oblivion Ring, Pacifism, or tappers like Kor Hookmaster, and Gideon's Lawmaker, Tamiyos' aspect of white also includes cards that only make combat disadvantageous for the opponent such as Mother of Runes and dauntless Cathar.
Maybe you should get a less narrow view of the color pie before you correct other people on how it works.
Then, you play Original Tamiyo, whose ultimate is:
"You get an emblem with "You have no maximum hand size" and "Whenever a card is put into your graveyard from anywhere, you may return it to your hand.""
She goes to the graveyard. Then you play new Tamiyo, whose ultimate makes your spells free.
Then you cast infinite token spells, direct damage or whatever else because your spells are free to cast and go back to your hand afterwards