Default theme does not load OS theme colours properly

[Nihlus]

When using a dark GTK theme on Linux, certain elements in the UI are too bright or have badly matched colours, making it difficult to see.

This is most apparent with the GTK theme enabled in settings, but is an issue with all themes. I believe the issue lies in hardcoded colours.

[slestak]

See #598

[serge-rider]

You can configure DBeaver specific colors in Preferences->General->Appearance->Colors and Fonts.

[andrei-gheorghiu]

Until someone with enough design skills spends some time to correct each color and export the result, a quick fix is to go to
Window > Preferences > General > Appearance

1. Check "Enable theming"
2. Theme: Dark

It's not as slick as GTK (or similar), but it makes the data readable.