In Commander does a card with a white hybrid mana symbol in its cost have white in its color identity?

In Commander, a card's color identity is determined by every mana symbol that appears anywhere on the card — in its mana cost, rules text, and characteristic-defining abilities. This is governed by CR 903.4 and CR 202.2.

Hybrid mana symbols, such as {W/U} or {W/B}, count as both colors they represent for the purposes of color identity (CR 202.2c). So a card with a {W/U} hybrid symbol in its cost has both white and blue in its color identity, regardless of how you actually pay for it.

This means the card cannot be included in a Commander deck unless the commander's color identity includes all colors represented by every hybrid symbol on the card. A mono-blue commander's deck could not include a card with {W/U} in its cost, because white is not in that commander's color identity.

Example: Kitchen Finks has {1}{W/G}{W/G} in its mana cost. Its color identity is both white and green. You can only play it in a deck whose commander has white and green in its color identity — such as Rhys the Redeemed, but not a mono-green commander like Omnath, Locus of Mana.

The key point: color identity for Commander does not care about what colors you could pay with — it cares about what colors are referenced by the symbols themselves (CR 903.4, CR 202.2c).