gray method
Set foreground to ANSI gray when called with no args (pen.gray),
or set to a xterm256 grayscale value when called with level:
(compatible with ansicolor's AnsiPen.gray() signature).
Implementation
AnsiPen gray({num? level, bool bg = false}) {
if (level != null) {
final int code = 232 + (level.clamp(0.0, 1.0) * 23).round();
styleStack.add(
bg ? QuectoColors.bgAnsi256(code) : QuectoColors.ansi256(code));
} else if (bg) {
styleStack.add(QuectoColors.bgGray);
} else {
styleStack.add(QuectoColors.gray);
}
return this;
}