相关的几个文件，或许更多

vim /etc/bash.bashrc
vim /etc/profile
vim ~/.bashrc
vim ~/.bash_profile

终端颜色由 PS1 变量进行定义，上面这些文件中就有 PS1 变量。
1.去掉 ~/.bashrc 中的 force_color_prompt=yes 注释，保存后并 source ~/.bashrc 之后如果终端颜色已经上色，这就达到目的了。
2.终端执行 export TERM=xterm-256color 开启256真彩色试试结果，如果有效，把这行代码追加到 ~/.bashrc 或者 /etc/profile 文件的末行。
3.试试下面的命令，其实就是开启 force_color_prompt=yes

# 首先将bashrc备份
cp /etc/bash.bashrc /etc/bash.bashrc.bak

# 将配置写入bashrc
cat << EOF >> /etc/bash.bashrc
# uncomment for a colored prompt, if the terminal has the capability; turned
# off by default to not distract the user: the focus in a terminal window
# should be on the output of commands, not on the prompt
force_color_prompt=yes
 
if [ -n "$force_color_prompt" ]; then
    if [ -x /usr/bin/tput ] && tput setaf 1 >&/dev/null; then
        # We have color support; assume it's compliant with Ecma-48
        # (ISO/IEC-6429). (Lack of such support is extremely rare, and such
        # a case would tend to support setf rather than setaf.)
        color_prompt=yes
    else
        color_prompt=
    fi
fiif [ "$color_prompt" = yes ]; then
    PS1='${debian_chroot:+($debian_chroot)}\[\033[01;32m\]\u@\h\[\033[00m\]:\[\033[01;34m\]\w\[\033[00m\]\$ '
else
    PS1='${debian_chroot:+($debian_chroot)}\u@\h:\w\$ '
fi
EOF