precmd() {
  # sets the tab title to current dir
  echo -ne "\e]1;${PWD##*/}\a"
}

PRELINE="\r\033[A"

function random {
    echo -e "\033]6;1;bg;red;brightness;$((1 + $RANDOM % 255))\a"$PRELINE
    echo -e "\033]6;1;bg;green;brightness;$((1 + $RANDOM % 255))\a"$PRELINE
    echo -e "\033]6;1;bg;blue;brightness;$((1 + $RANDOM % 255))\a"$PRELINE
}

function color {
    case $1 in
    green)
    echo -e "\033]6;1;bg;red;brightness;57\a"$PRELINE
    echo -e "\033]6;1;bg;green;brightness;197\a"$PRELINE
    echo -e "\033]6;1;bg;blue;brightness;77\a"$PRELINE
    ;;
    red)
    echo -e "\033]6;1;bg;red;brightness;270\a"$PRELINE
    echo -e "\033]6;1;bg;green;brightness;60\a"$PRELINE
    echo -e "\033]6;1;bg;blue;brightness;83\a"$PRELINE
    ;;
    orange)
    echo -e "\033]6;1;bg;red;brightness;227\a"$PRELINE
    echo -e "\033]6;1;bg;green;brightness;143\a"$PRELINE
    echo -e "\033]6;1;bg;blue;brightness;10\a"$PRELINE
    ;;
    *)
    random
    esac
}

color