Microsoft recently released a new preview build of Skype for Android, iPhone, iPad, Mac, Linux, Linux Snap, Web, Desktop app & Store app for Windows 10 PC. This version 18.104.22.168 build comes with redesigned theme picker and new color gradients.
First, Microsoft has simplified the theme picker by combining the theme picker and color. Under Settings menu, you can find the Appearance drop down.
Second, the new color gradients feature higher contrast, improved visibility and now allows you to control whether the color accents affect your message bubble or the bubbles of the people you’re messaging with.
Try these features and provide your feedback to Skype team to refine the experience.