function bgRgb24
bgRgb24(): stringSet background color using 24bit rgb.
color can be a number in range 0x000000 to 0xffffff or
an Rgb.
To produce the color magenta:
import { bgRgb24 } from "@std/fmt/colors"; bgRgb24("foo", 0xff00ff); bgRgb24("foo", {r: 255, g: 0, b: 255});