I use the latest release of Fusion 12 (16880131) on i iMac (late 2015 + macOS 11.0.1). I run some macOS VM and all the Safari tab have wrong colors, so I can't understand whis is the one active.
The VMs now run the latest release of Catalina, but this happened also with older version of macOS (both host and guest).
Does sombody experienced somthing similar?
It's because a macOS VM does not have hardware acceleration and thus no support for rendering via metal.
This is in the works and can actually be enabled as an experimental feature.
More info here:
It was very unstable on earlier Big Sur releases (unworkable really) seems it might be more stable now with the latest Big Sur beta versions.