rgb method
Sets the pen color to the rgb value between 0.0..1.0.
Implementation
void rgb({num r = 1.0, num g = 1.0, num b = 1.0, bool bg = false}) => xterm(
(r.clamp(0.0, 1.0) * 5).toInt() * 36 +
(g.clamp(0.0, 1.0) * 5).toInt() * 6 +
(b.clamp(0.0, 1.0) * 5).toInt() +
16,
bg: bg);