My git branch prompt, colorizes the branch based on status. Might need some work on the colors as yet. Apart from the definition, works in bash or ksh.

git_prompt.sh

function _git_prompt() {
    local _branch=`git branch --no-color 2> /dev/null | sed -ne 's/^* //p'`
    [[ -z $_branch ]] && return

    local _bgcolor
    local _color

    for s in `git status --porcelain | tr ' ' '.' | cut -c 1-2`; do
        if [ -z "$_color" ]; then
            case "$s" in
               ?D)   _color='\e[35m' ;;
               ?M)   _color='\e[36m' ;;
               \?\?) _color='\e[33m' ;;
            esac
        fi
        if [ -z "$_bgcolor" ]; then
            case $s in
               A?) _bgcolor='\e[43m' ;;
               D?) _bgcolor='\e[41m' ;;
               M?) _bgcolor='\e[44m' ;;
            esac
        fi
    done

    # Highligh it we haven't done a git pull today
    local now=`date +%s`
    local last_pull=0
    local fetch_head=$( git rev-parse --show-toplevel )/.git/FETCH_HEAD 
    [ -e $fetch_head ] && last_pull=`stat -c %Y $fetch_head`
    age=$(( $now - $last_pull ))

    if [ $age -gt 86400 ]; then
        _color='\x1b[5m'$_color
    fi
    
    _color=${_color:-'\e[32m'}
    #_bgcolor=${_bgcolor:-'\e[42m'}
    echo -en "\[\e[0m\]{\[$_bgcolor$_color\]${_branch}\[\e[0m\]}"
}

prompt_cmd() {
    PS1="\n[$(date +%H:%M)]-[\u@\h: \w] $(_git_prompt) \$ "
}