General Tazri — ruling 1

The last ability checks only Ally creatures you control as the ability resolves. The value of X will be between 0 and 5. Colorless is not a color.

General Tazri — ruling 2

Once the last ability resolves, the bonus given doesn’t change, even if the number of colors among your Allies does.

General Tazri : règles, fonctionnement et interactions (MTG)

General Tazri is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

When General Tazri enters, you may search your library for an Ally creature card, reveal it, put it into your hand, then shuffle. : Ally creatures you control get +X/+X until end of turn, where X is the number of colors among those creatures.

How it works : General Tazri

Original English text — Wizards of the Coast / Scryfall

#1January 22, 2016· Wizards of the Coast
The last ability checks only Ally creatures you control as the ability resolves. The value of X will be between 0 and 5. Colorless is not a color.
No other card is named in this ruling.
#2January 22, 2016· Wizards of the Coast
Once the last ability resolves, the bonus given doesn’t change, even if the number of colors among your Allies does.
No other card is named in this ruling.