This is a very simple prompt with only different colors:

PS1="\[\e[0;37m\][\[\e[0;32m\]\u\[\e[0;37m\]@\[\e[0;33m\]\h\[\e[0m] "

Some scripting foo to get a different color for root (for better readability split into multiple lines):

PS1=""
# add user
if [[ ${EUID} == 0 ]]; then 
        PS1+="\[\e[0;31m\]\u"
else
        PS1+="\[\e[0;32m\]\u"
fi
# add @ + host
PS1+="\[\e[0;37m\]@\[\e[0;33m\]\h "

Now adding some brackets and the working directory:

# opening brackets
PS1="\[\e[0;37m\]["
# add user
if [[ ${EUID} == 0 ]]; then 
        PS1+="\[\e[0;31m\]\u"
else
        PS1+="\[\e[0;32m\]\u"
fi
# add @ + host
PS1+="\[\e[0;37m\]@\[\e[0;33m\]\h"
# add working dir
PS1+="\[\e[0;37m\]:\[\e[01;34m\]\w"
# closing brackets + reset 
PS1+="\[\e[0;37m\]]\e[0m "

Now some functionall things.
I'm using the prompt_command to add last exit code to my prompt. Short descriptione from the bash man page:

PROMPT_COMMAND
If set, the value is executed as a command prior to issuing each
primary prompt.

Adding last exit code:

function prompt () {
        exitcode=$?
        # add exit code
        PS1=" "
        if [ $exitcode == 0 ]; then
                PS1+="\[\033[01;32m\]\342\234\223"
        
        else
                PS1+="\[\033[01;31m\]\342\234\227"
        fi

        PS1+="$exitcode "
        # opening brackets
        PS1+="\[\e[0;37m\]["
        # add user
        if [[ ${EUID} == 0 ]]; then
                PS1+="\[\e[0;31m\]\u"
        else
                PS1+="\[\e[0;32m\]\u"
        fi
        # add @ + host
        PS1+="\[\e[0;37m\]@\[\e[0;33m\]\h"
        # add working dir
        PS1+="\[\e[0;37m\]:\[\e[01;34m\]\w"
        # closing brackets + reset 
        PS1+="\[\e[0;37m\]]"
        # reset color
        PS1+="\e[0m "
}
PROMPT_COMMAND='prompt'

Combinig all this stuff with one of my last posts, it could look like this:

function prompt () {
        exitcode=$?
        # add exit code
        PS1=" "
        if [ $exitcode == 0 ]; then
                PS1+="\[\033[01;32m\]\342\234\223"
    
        else
                PS1+="\[\033[01;31m\]\342\234\227"
        fi  
    
        PS1+="$exitcode "
        # opening brackets
        PS1+="\[\e[0;37m\]["
        # add user
        if [[ ${EUID} == 0 ]]; then 
                PS1+="\[\e[0;31m\]\u"
        else
                PS1+="\[\e[0;32m\]\u"
        fi  
        # add @ + host
        PS1+="\[\e[0;37m\]@\[\e[0;33m\]\h"
        # add working dir
        PS1+="\[\e[0;37m\]:\[\e[01;34m\]\w"
        # closing brackets + reset 
        PS1+="\[\e[0;37m\]]"
        # display git branch
        if [ -f /usr/bin/git ]; then
                branch="$(git branch --no-color 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/ \(\1\)/')"
                PS1+="$branch"
        fi  
        PS1+=" \$"
        # reset color
        PS1+="\e[0m "
}
PROMPT_COMMAND='prompt'