Header layout value from master pages

Hello,

I am creating a website which consists of three parts:

mydomain.test/zonnepanelen/

mydomain.test/led-verlichting/

mydomain.test/infraroodverwarming/

All pages and subpages are created from masterpages, because the pages are the same but the content is different. I have created css files to change color, so all three pages have to have different css files:

mydomain.test/zonnepanelen/ - green.css

mydomain.test/led-verlichting/ - blue.css

mydomain.test/infraroodverwarming/ - yellow.css

I have one header layout for all pages.

Now in my header.php layout I have tried the following conditional:

    <?php
        if (perch_layout_has('green')) {
            echo '<link href="/css/green.css" rel="stylesheet">';
        } else if (perch_layout_has('blue')) {
            echo '<link href="/css/blue.css" rel="stylesheet">';
        } else {
            echo '<link href="/css/yellow.css" rel="stylesheet">';
        }
    ?>

and in my masterpage:

<?php
    perch_layout('header', array(
        "blue" => true
    ));
?>

So, how can I pass the layout value to those pages when they are all coming from the same master page? I hope this explanation makes sense.

Mike