# Check for an interactive session
[ -z "$PS1" ] && return

_PROMPT() {
    _EXIT_STATUS=$?
    [ $_EXIT_STATUS != 0 ] && _EXIT_STATUS_STR="\[\033[1;30m\][\[\033[1;31m\]$_EXIT_STATUS\[\033[1;30m\]] "
    PS1="\033[1;30m\]» \[\e[0;33m\]fu\033[1;30m\]╺─╸$_EXIT_STATUS_STR\[\033[1;30m\][\[\033[0m\]\W\[\033[1;30m\]]\[\033[1;34m\];\[\033[0m\] "
    unset _EXIT_STATUS_STR
}

PROMPT_COMMAND=_PROMPT


Result: 

» fu╺─╸[~];  with the defined colors.