MTG Commander Color Identity Checker

In Commander (EDH), your commander dictates which colors your whole deck may use: every card’s color identity must be a subset of the commander’s. This checker parses the mana symbols you paste, derives each card’s color identity using the real rule, and flags anything that strays outside your commander’s colors.

How it works

A color identity is the set of the five colors — White, Blue, Black, Red, Green — that appear as mana symbols anywhere on a card. The tool scans each brace group in your input. Generic numbers and colorless symbols add nothing; each colored letter inside a group adds that color, so a hybrid pip {W/U} contributes both white and blue.

A card is legal when:

card_identity ⊆ commander_identity

In words, every color the card uses must also be a color the commander allows. If a card introduces even one extra color, the deck-building rules make it illegal.

Example and tips

With a mono-red commander (identity R), Lightning Bolt {R} is legal but Boros Charm {R}{W} is illegal because of the white pip. Set the commander to a Boros (R/W) identity and both become legal. Remember to include colored symbols that appear in rules text — a land that adds {G} or a creature with a {B} activated ability carries that color even if its casting cost is colorless. Paste those symbols on the line so the checker can see them.

The Commander color identity rule — all the edge cases

The color identity rule in EDH catches more cards than most players initially expect. Here are the most common edge cases to check:

Lands with colored mana symbols in rules text

A basic land taps for one color naturally, but no mana symbol appears in its rules text — it just says “add {G}” in natural-language form. However, non-basic lands and dual lands that have mana symbols in their oracle text carry those colors in their identity.

For example, a land that says “tap: add {W} or {U}” has both white and blue in its identity, even with a colorless casting cost. This means it is illegal in a mono-red or green-black deck. Paste the colored symbols you see in the card’s text box into the checker to verify.

Hybrid mana and Phyrexian mana

Hybrid mana symbols like {W/U} contribute BOTH colors. A card with {G/W} in its cost has both green and white in its color identity — it cannot go into a Simic (G/U) deck because white falls outside.

Phyrexian mana symbols like {G/P} still contribute their color to the card’s identity, even though the Phyrexian mana can be paid with life rather than green mana. The ability to pay life does not remove the green color from the identity.

Split cards, Adventures, and modal cards

For cards with multiple faces or modes (split cards, Adventures, sagas, battles):

• All mana symbols from all modes and faces contribute to identity
• A split card that is {R}{R} // {B}{B} has both red and black in its identity and requires a commander with both

The color indicator

Some cards have a colored oval on the type line (the “color indicator”) rather than a colored mana cost. These cards, like certain basic land types or Devoid cards in Eldrazi sets, get their identity from that indicator. Devoid cards, however, have a specific rule: the Devoid keyword makes the card colorless, overriding the colored casting cost for color purposes.

Quick reference: common identity check scenarios

Note: Command Tower’s text says it produces mana of any color in your commander’s identity. The mana symbols it produces are variable and derived from the deck’s identity — the card itself has no fixed colored symbol, so it has a colorless identity and goes in any Commander deck.

Using this checker effectively

For best results when pasting a card list into the checker:

• Include all colored mana symbols that appear on the card, both in the casting cost and in the rules text
• Format each card as one per line: Card Name {mana symbols}
• Hybrid symbols can be entered as {W/U}, Phyrexian as {W/P}
• Generic mana {1}, {2}, etc. and colorless {C} add nothing to identity and can be omitted if you prefer