def _translate_theme(theme_value: str) -> str:
    """Translate the theme from CLI value to pygments theme."""
    theme_alias = {
        "dark": "ansi_dark",
        "light": "ansi_light",
    }
    lowered_theme_argument = theme_value.lower()
    pygments_theme = theme_alias.get(lowered_theme_argument, lowered_theme_argument)
    return pygments_theme