preformatted block background

I’ve used a block called “preformatted” to post a poem on my website. I used this rather than the block called “verse” because the preformatted block actually let me indent lines with white space, which the verse block didn’t.

However, the preformatted block seems to have a semi-transparent background. I want to remove that, but I can’t find how to do so.

Can anyone help?

Thanks,

John

The page I need help with: [log in to see the link]