How to change text color depending on the number value (Using javascript)

I'm trying to change text on the table depending on the meta value I give (number).

• if meta value = 7, number text on table changes to green.
• else if meta value = 4, number text on table changes to yellow.
• else, number text on table changes to red.

However, this code doesn't work.

script type=text/javascript
    function change_color_text (num1) {
        var rate_num = num1;
        if(rate_num = 7) {
            rate_num.style.color = green; // green
        } else if (rate_num = 4) {
            rate_num.style.color =  yellow; // yellow
        } else {
            rate_num.style.color = red; // red
        }
    return rate_num;
    }
/script

?php $ccf_CAR = get_post_meta( get_the_ID(), 'ccf_CAR', true ); ? // meta data is number value like 7,2,5 etc. (This code is working)
?php $ccf_PSC = get_post_meta( get_the_ID(), 'ccf_PSC', true ); ? // meta data is number value like 7,2,5 etc. (This code is working)

figure class=wp-block-table
    table
        thead
            tr
                thRate Subject/th
                th class=has-text-align-center data-align=centerStatus/th
            /tr
        /thead
        tbody
            tr
                tdSafe Score/td
                td class=has-text-align-center data-align=centerp id=safe_score?php echo script change_color_text($ccf_CAR); /script; ?/p/td
            /tr
            tr
                tdPrice Score/td
                td class=has-text-align-center data-align=centerp id=price_score?php echo script change_color_text($ccf_PSC); /script?/div/td
            /tr
            ....same code above for the table
        /tbody
    /table
/figure

I think there's an error in javascript function or maybe I didn't write properly with this code.

?php echo script change_color_text($ccf_CAR); /script; ?