In testing 6.3 beta 3, I noticed that the "randomize colors" was listed as an option in Styles. This is an experimental option for Gutenberg and, unless something changed, should not be in 6.3:

Furthermore, I can still see it listed as an unworkable button in GB 16.1.1 so something must have gone wrong here. Here are the related PRs for this feature in case it helps: #40988 #51539

Here's a video of the current experience:

cc @tellthemachines @ramonjd as Core Editor tech leads!