By default, your ~/.bashrc contains a section that defines the ls and grep commands to run in color mode.

The default .bashrc configuration file can be found in the directory /etc/skel, and from here you can take the relevant section and add it back to your ~/.bashrc to restore the default behavior with color support:

# enable color support of ls and also add handy aliases

if [ -x /usr/bin/dircolors ]

then

    test -r ~/.dircolors && eval "$(dircolors -b ~/.dircolors)" || eval "$(dircolors -b)"

    alias ls='ls --color=auto'

    alias dir='dir --color=auto'

    alias vdir='vdir --color=auto'



    alias grep='grep --color=auto'

    alias fgrep='fgrep --color=auto'

    alias egrep='egrep --color=auto'

fi