Prints xterm colours.
By default colours are sorted by RGB value. Use flags for different sorting:
$ colours # Default RGB sorting
$ colours -dist=21 # Sort by distance from colour 21 (valid: 16-231)
$ colours -grey # Sort by grayscale value
$ colours -harm=21 # Show colour harmonies for colour 21 (valid: 16-231)
$ colours -hue # Sort by hue (rainbow order) with greys separated
$ colours -lum # Sort by luminance (brightness)
$ colours -sat # Sort by saturation (vibrancy)
$ colours -sim # Sort by visual similarity groups
$ colours -temp # Sort by temperature (warm/cool)
$ go install github.com/jsageryd/colours@latest