【参考】
qiita.com
例)
DEV(水色)
echo '[ "$PS1" = "" ] || PS1="[\u@\[\e[1;46m\]\h\[\e[0m\] \W] \$ "' >> /etc/profile.d/prompt.sh
STG(緑色)
echo '[ "$PS1" = "" ] || PS1="[\u@\[\e[1;42m\]\h\[\e[0m\] \W] \$ "' >> /etc/profile.d/prompt.sh
PROD
echo '[ "$PS1" = "" ] || PS1="[\u@\[\e[1;41m\]\h\[\e[0m\] \W] \$ "' >> /etc/profile.d/prompt.sh
※
chmod +x /etc/profile.d/prompt.sh
しておくこと