I first tried Safari 4 on a Windows XP machine and while the Safari-part looked great (with its new Speed Dailesque start page) the top-bar (where the tabs sit) looked horrible.
The Safari 4 tabs on Windows XP in my opinion are the worst design elements of any Apple product I’ve ever seen. Let me describe those tabs to you. First, imagine that your tabs are the width of your thumb. Then picture them being an ocean-deep blue. Now think of Apple with their smooth polished metal chome-look. Does that fit? No, it doesn’t.
Now, tabs on Windows Vista are dramatically improved but there are still problems. Firstly, the horrendous ocean-deep blue bar from XP is gone. Instead, we get a Chrome-like (the browser) tab bar that is transparent and smooth. Each of the tabs have a bit of special lighting applied to them to make them look fancy but oddly none of them tabs light up when you mouse over them. I add this because for some reason, the lighting is applied on top of black text on the translucent tabs so it obscures your unfocused tabs, it does however show the current tab well.
Next, I tried Safari 4 on Windows 7. You have to understand that I don’t change the default theme for anything. So, XP has it’s Royal blue and Vista has it’s black and Windows 7 has it’s median color. I get what it comes with. This note is important because I think it has a major impact on the way tabs show up. In Windows 7, the tabs look similar to those in Vista but are much lighter. The problem noted above about Vista isn’t present in Windows 7.
I’m still stunned on how they let those Windows XP Safari tabs pass. They’re just out of the entire theme of Apple.