
Crème de menthe green is a sweet, mint-flavored liqueur dyed bright green. The same product is also sold colorless as "white".
Mint is the flavor and color is the only variable, so the question is whether the drink should stay pale. Fresh mint gives the aroma without the sugar, which then has to come from somewhere else.
White crème de menthe
Both are sweetened peppermint liqueurs; the white one simply goes uncolored. They taste alike, so the choice is only whether the drink comes out green or clear.
The mint itself keeps indefinitely; the green does not. The color is added, and daylight will pull it toward yellow over a season on a sunny back bar. Store it out of the light if the drink depends on the color, which with this bottle it usually does.