When you have some underlined text on a WebView (like a link), the width of the line is 2px instead of 1px and color is 50% of what it should be (for example, instead of #000, the line will be #808080).

It seems that lines are being antialiased, or at least drawn in half pixel coordinates (or viceversa).

I've also tested this with the latest JavaFX 8, and the same happens.