As of now, pastel show ff0000 shows the following:

I think that it'd be useful to add a Name: section where to put the name of the color if it has one. Also, I think that hiding it from the most similar list makes sense because it is that color after all.

I have played around with this idea a bit and came up with

If you think that's something worth having then I'm happy to submit a PR, otherwise feel free to close this issue. Let me know what you think.