使用case语句给字体改变颜色

#!/bin/bash
color(){
RED_COLOR=‘\E[1;31m‘
GREEN_COLOR=‘\E[1;32m‘
YELLOW_COLOR=‘\E[1;33m‘
BLUE_COLOR=‘\E[1;34m‘
PINK_COLOR=‘\E[1;35m‘
RES=‘\E[0m‘
if [ $# -ne 2 ];then
        echo "Usage $0 content {red|yellow|blue|green}"
        exit
fi
case "$2" in 
        red|RED)
                echo -e "${RED_COLOR}$1${RES}"
                ;;
        yellow|YELLOW)
                echo -e "${YELLOW_COLOR}$1${RES}"
                ;;
        green|GREEN)
                echo -e "${GREEN_COLOR}$1${RES}"
                ;;
        blue|BLUE)
                echo -e "${BLUE_COLOR}$1${RES}"
                ;;
        pink|PINK)
                echo -e "${PINK_COLOR}$1${RES}"
                ;;
        *)
                echo -e "${PINK_COLOR}$1${RES}"
esac
}
color haha red
color haha yellow
color haha green
color haha blue
color haha pink
color haha feaf