compare the checksum of all files with the same name in 2 different folders

sh

#!/bin/bash

CERROR='\033[0;31m' #Error color
COK='\033[0;32m' #Error color
NC='\033[0m' # No Color

IFS=$'\n'
offset=$(( ${#1} + 1))

fnames=`find ${1} -type file -not -path '*/.*'`

for f in ${fnames}
do
        s1=`shasum -a 256 ${f} | awk '{ print $1 }'`
        s2=`shasum -a 256 ${2}/${f:$offset} | awk '{ print $1 }'`
        if [ "$s1" != "$s2" ]; then
                printf "${CERROR}ERROR \\t${NC}${f:$offset}\n"
        else
                printf "${COK}OK \\t${NC}${f:$offset}\n"
        fi
done

more precisely, for all files in the first folder and its subfolders, it checks in the second directory if any other file with the same name and path as in the one in the first folder has the same checksum or not and displays a message OK or ERROR respectively with the path/filename of the file.
OK is green. ERROR is red.