I admire seeing WordPress move forward keeping accessibility as a priority after its misstep in the 5.0 release. These buttons are a continuation of this priority.
However, it’s disappointing to see a block of form controls and buttons that are too close in design aesthetic to each other.
The image I attached in my previous post is what I see on the comments list page in the Dashboard. I see multiple UI and UX problems with the above block.
I could list out the problematic state changes that are hard to see to the nearly identical styles between input fields and buttons. Inconsistent component heights, confusing applied border colors, Midnight Admin Color Scheme active button state on “Search Comments” button being completely red, and more are things I would attribute to not enough QA and testing for this release.
I think this mini-audit above should give you enough alarm to resolve these issues asap, in the next point releases.