I think the color variation would help me better process what I’m looking at.
You can change the color yourself btw. The traditional method is to install the Stylus extension/addon, but I think kbin now lets you define your own styling in your profile settings, though I haven't tried it. (tried it now and this doesn't really seem possible there, has the same selector deletion issues as magazine css)
In the HTML code, microblog posts and threads are represented differently. Posts are blockquote, while threads are article. This makes it easy to restyle them via userstyles.