Comment 3 for bug 1313366

The attached screenshot is displaying the problem as mentioned by the original reporter.
Using high-contrast theme the offset is not displayed at all, because black font is used on black background.

Suggestion: provide preferences for back- and foreground-colors.

Workaround:
As matter fo fact me and my colleague switched to bless instead of ghex since it provides all the settings to customize the UI and works really well.