RT Show RBG values as x/255 rather than percentage?

[heckflosse (Ingo Weyrich)]

@Claes

If you are going to try this from github, please note that you will need two new dependencies:gtkmm-2.4 and libcanberra (both the dev variety).

If you built from master branch (not gtk3) in past there are no new dependencies (at least for Windows, didn’t try on Linux yet, but would not expect additional dependencies there too)

Ingo