Commander or edh is a format that, amongst other things places restrictions on the colours of the cards you play in the deck. See this faq.
A card's color identity is its colour plus the color of any mana symbols in the card's rules text. A card's color identity is established before the game begins, and cannot be changed by game effects. Cards in a deck may not have any colors in their color identity which are not shared with the Commander of the deck. (The identity of each card in the deck must be a subset of the Commander's)
But if I have a card like flash conscription which has a rider on which colour of mana was used, can I put that into a deck that doesn't have that colour identity, and can I pay for it with something like a treasure token or some other effect that can make any colour mana?