value is unset but why

Question

I have a script that keeps unsetting the value but I cant find why. In the case below the output is:

green Physical drive in slot 2I:1:1 (size : 146.8GB) status is OK
green Physical drive in slot 2I:1:2 (size : 146.8GB) status is OK
green Physical drive in slot 2I:1:3 (size : 146.8GB) status is OK
yellow Physical drive in slot 2I:1:4 (size : 146.8GB) status is BAD !!!
green Physical drive in slot 2I:1:5 (size : 146.8GB) status is OK

I need the value Yellow to trigger my monitor. But yellow is changed in the loop and I can't find what I'm doing wrong

$HPACUCLI ctrl all show config | grep drive | while read OUTPUT ; do

    TYPE=$(echo $OUTPUT | awk '{print $1}' | sed s/drive//)
    SLOT=$(echo $OUTPUT | awk '{print $2}')
    STATUS=$(echo $OUTPUT | awk '{print $NF}' | sed s/\)//)
    if [ "$STATUS" == "spare" ] ; then
        STATUS=$(echo $OUTPUT | cut -d',' -f4 | sed 's/ //g')
    fi

    if [ "$TYPE" == "physical" ] ; then
        SIZE=$(echo $OUTPUT | awk '{print $8 $9}' | sed s/\,//)

        if [ "$STATUS" != "OK" ] ; then
            YELLOW=1
            echo "Yellow" "$YELLOW"
            LINE="&yellow Physical drive in slot $SLOT (size : $SIZE) status is BAD !!!"

        elif [ "$STATUS" == "OK" ] ; then
            echo "Yellow" "$YELLOW"
            LINE="&green Physical drive in slot $SLOT (size : $SIZE) status is OK"
        else
            echo "Yellow" "$YELLOW"
            RED=1
            LINE="&red Unknow status (or stupid monitoring script) for physical drive in slot $SLOT \(size : $SIZE\) !!!"
        fi
    fi

    echo $LINE >> $MSG_FILE
done

echo "Yellow" "$YELLOW"

The output when running is:

Yellow
Yellow
Yellow
Yellow 1
Yellow 1
Yellow

Why is the last Yellow not 1 ??