textarea height adjuster

Hi,
This is a bit tricky.. but is there a css ( or other )possible way to change the color of the text field height adjuster ? ( the selector in the down-right corner of the field that makes the field height bigger )
We can't find something..
Thanks in advance

Hi siteworksgr,
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Please post a link to your form page so we can take a quick look there.
​
Bob

Thanks.
The link is https://odme.de/contact-us

Hi siteworksgr,
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Sorry, but I don't see a height adjuster; checked with a couple of browsers and on my phone.
​
Bob

Hi again,
I'm sorry , maybe I don't use the right term, but I mean the one adjuster, in the right down corner of the form

Hi siteworksgr,
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Yes, that is what I looked for - but I don't see it :-(
​
Bob

this is very strange... 🙄

Hi siteworksgr,
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It's evening here and I'm using my iPad, I'll check on my desk-top PC tomorro.
​
Bob