The color used when highlighting duplicated lines of code needs to have more of a contrast on a white background. Right now the duplicated code indicator on the “Measures → Duplications → Select file” screens is light gray on a white background. It is really hard to notice, especially when it is only identifying a single line or if the file is large.
Please update this to be something that is easier to find/notice and/or having a UI feature that only shows which lines are considered duplicated lines.