Procs

proc rgb_to_yiq(red, green, blue: float): tuple[y, i, q: float] {.
    ...raises: [Exception, ValueError, OSError, IOError, EOFError, KeyError],
    tags: [RootEffect].}

proc yiq_to_rgb(y, i, q: float): tuple[red, green, blue: float] {.
    ...raises: [Exception, ValueError, OSError, IOError, EOFError, KeyError],
    tags: [RootEffect].}

proc rgb_to_hls(red, green, blue: float): tuple[
    hue, lightness, saturation: float] {.
    ...raises: [Exception, ValueError, OSError, IOError, EOFError, KeyError],
    tags: [RootEffect].}

proc hls_to_rgb(hue, lightness, saturation: float): tuple[
    red, green, blue: float] {....raises: [Exception, ValueError, OSError, IOError,
                                        EOFError, KeyError], tags: [RootEffect].}

proc rgb_to_hsv(red, green, blue: float): tuple[hue, saturation, value: float] {.
    ...raises: [Exception, ValueError, OSError, IOError, EOFError, KeyError],
    tags: [RootEffect].}

proc hsv_to_rgb(hue, saturation, value: float): tuple[red, green, blue: float] {.
    ...raises: [Exception, ValueError, OSError, IOError, EOFError, KeyError],
    tags: [RootEffect].}