As the primary designer/developer of the current site, I’d be quite happy to not have the current logo, or color scheme I derived from it. I also like—at a glance—the Plex lower case g; though aside from that, it is very similar to the current typeface, Muli, which, again, is derived from the logo.
What you may not be aware of is that the current color scheme of the logo may be related to the Go language’s gopher mascot and that the original design (from 2013-14) was meant to convey friendliness and fun, which those colors do convey. I don’t see any of that in your mockup (because you didn’t ask first).
I think if Hugo were to go through a branding there should be a brief with careful consideration of these factors. Suddenly showing up to say the entire site is “weak” is not a great place to start.
What I think would be productive, if you really really want to contribute, would be some help in other, more incremental regards. The icons just below the news section all have different line widths (they were the only thing I could find at the time) and need improvement. We could use better icons for Twitter and GitHub and there are specific sections of the site that could use some fresh ideas, that I or others would be happy to discuss.
and for what it’s worth, Hugo already is one of the most popular static site generators in the world.