3-4 bit and 256-color ansi output

colors.js

console.log('3-4 bit:')
const lows = []
for (let c = 30;c<=37;c++) {
  lows.push(`\x1b[${c}m${c}\x1b[0m`)
}
console.log(lows.join(' '))
console.log('256 color:')
let mediums = []
for (let c = 0;c<=231;c++) {
  if (!(c % 16)) { // new row
    if (mediums.length) {
      console.log(mediums.join(' '))
    }
    mediums.length = 0
  }
  mediums.push(`\x1b[38;5;${c}m${c}\x1b[0m`)
}
console.log(mediums.join(' '))