In Commander, can you use your commander's color identity to play off-color lands like Reflecting Pool that can produce any color?

In Commander, the color identity rule (CR 903.4) states that each card in your deck must have a color identity that is a subset of your commander's color identity. A card's color identity is determined by its mana cost, color indicator, and any mana symbols appearing in its rules text (CR 202.2).

Reflecting Pool's color identity is colorless — it has no mana symbols in its cost or rules text that define a color identity. This means it is legal in any Commander deck regardless of your commander's colors. However, its ability to actually produce off-color mana at runtime is a completely separate question from deck legality.

Importantly, what colors Reflecting Pool can produce depends on what colors your other lands could produce (CR 305.6 for the Pool's templating). If you're in a mono-red deck, Reflecting Pool can only produce red mana (matching your other lands). It does NOT grant you access to colors outside your commander's identity — it simply mirrors what your other lands can already do.

Concrete example: You're playing a Mono-Red commander. Reflecting Pool is legal in your deck (colorless identity). However, if all your other lands only tap for red mana, Reflecting Pool can only tap for red mana too. It won't produce blue, green, or any other off-color mana.

So the short answer: Reflecting Pool is always legal to include in any Commander deck, but it will never let you produce mana of colors outside your commander's identity, because it can only copy what your other lands could already produce.