Problem with Improve "Readability with High Contrast Text"

Tell us what’s happening:
I´ve changed ONLY the color from #D3D3D3 to #636363 and still gives me these errors
Your code so far


<head>
<style>
body {
  color: #636363;
  background-color: #FFF;
}
</style>
</head>
<body>
<header>
  <h1>Deep Thoughts with Master Camper Cat</h1>
</header>
<article>
  <h2>A Word on the Recent Catnip Doping Scandal</h2>
  <p>The influence that catnip has on feline behavior is well-documented, and its use as an herbal supplement in competitive ninja circles remains controversial. Once again, the debate to ban the substance is brought to the public's attention after the high-profile win of Kittytron, a long-time proponent and user of the green stuff, at the Claw of Fury tournament.</p>
  <p>As I've stated in the past, I firmly believe a true ninja's skills must come from within, with no external influences. My own catnip use shall continue as purely recreational.</p>
</article>
</body>

  **Your browser information:**

User Agent is: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.82 Safari/537.36.

Challenge: Improve Readability with High Contrast Text

Link to the challenge:

What’s that stuff by the head tag. Get rid of it. I passed it, but it failed when I add that extra stuff. The tests FCC runs are simple. They only allow for the exact change they want you to make. Other characters will cause them to fail. Usually.

it’s a screenshot in the wrong place

@lucas.iraldi : I’ve edited your post to move the screenshot outside the code block

now, for your issue
you can’t use the dark reader extension while doing the css challenges, it is changing the css being tested