And that was really just about comparing simple RGB values!I'm sure we all remember this one from the early days of the internet: https://www.jagranjosh.com/general-knowledge/optical-illusion-grey-squares-1649739440-1
The case work of the Vibelink Amp, Ultra, Amp Pro and Amp are not simply painted in one uniform colour. They really do look different depending on angle, lighting and so on. So, depending on boundary conditions, the WiiM Ultra can really look like shown in the original post. In most real life conditions it doesn't look that dark, admittedly.