Getting URL from category item

Hello guys, i am currently making a small presentation website for a client and i got some trouble with perch categories. I have few pages with colors in it and each of them contains about 50 different colors. One of the pages is named "standard colors". Additional i have a "color search" page where i can filter all my colors by color tone. So far it works as i wanted to. If i click on red tones, i get all colors associated to the category red.

But heres my problem: I want to link each color i receive in my color search to its original page.

My first attempt was to use

PerchSystem::set_var('var_url', perch_page_url([], true));

but this doesn't work. The original color shows the url but i cant pass it to the color search. Maybe you know a better way to achieve this.

Heres the code of my two templates:

color template

<li>
    <span>
        <span class="m-color" style='background-color:#<perch:content id="colorcode" type="text" label="Color Value" textile="true" replace="#|" help="Hex Value with or without hash prefix (e.g. #ff0000 / ff0000)" />;'></span>
        <perch:content id="colorname" type="text" label="Color Name" textile="true" title="true" />
    </span>

</li>
<perch:categories id="color" label="Category" set="Colors" required="true"/>
<perch:content id="var_url" type="hidden" suppress="false"/>

color search template

<li>
    <a href='<perch:content id="var_url" type="hidden" />'>
        <span class="m-color" style='background-color:#<perch:content id="colorcode"/>;'></span>
        <perch:content id="colorname"/>
        <p>url: <perch:content id="var_url"/></p>
    </a>
</li>

I appreciate your help and thank you in advance! Greetings, Bastian