I really do not like the colors of the icons in macOS golden gate. The battery percentage is now inside the battery, which makes it so hard to read! Especially the mail app icon is too blue for me. Everything is just so ugh. I don't like it.
MacBook Air 13″
You can provide Apple with feedback:
I agree the new battery icon design is absolutely terrible. I first saw it on my new iPhone 17 with iOS26. I cannot read it most of the time. Apple has definitely lost their way with visual design aspects of both macOS & iOS.
I don't know whether there are any configuration options for your issue with the Mail app as I don't use it. Do you mean the Mail app's application icon or an icon used within the Mail app itself?
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