I agree. I couldn't get over any of the existing themes, they just seem so low contrast... So I spent a bunch of hours porting then favorite theme I've been using in Sublime Text, to Zed, named iPlastic. Sublime Text has a theme back of classic TextMate themes, and it came in that pack. I have to say, the porting process was not very easy, but it was worth it. Now, I prefer Zed to ST and VSCode because of the theme, not just the UI and other features :)