> More than just a refreshed set of graphics, Supernova introduces beautiful icons with a more consistent visual style unique to Thunderbird. Our new designs remain sharp and pixel-perfect at any density setting.
Translation: We break with the established platform look&feel to follow the brave trend of replacing easily identified colourful icons with vague monochrome silhouettes.
Pointless complaint with no actual observation of the new look and feel, Thunderbird is still just as colorful as it was before. The focus here seems to be on making the icons more consistent across the application as opposed to some of the issues they had before.
Translation: We break with the established platform look&feel to follow the brave trend of replacing easily identified colourful icons with vague monochrome silhouettes.