Image Viewer is not moved back to main dialog after adding to Color Picker dialog.

Mapillary/src/main/java/org/openstreetmap/josm/plugins/mapillary/gui/ImageColorPicker.java

Line 93 in c141f5b

    
           add(MapillaryMainDialog.getInstance().imageViewer, GBC.std().insets(5).weight(1, 1).fill());

Here the image viewer is added to a color picker dialog which removes it from the main dialog and is never added back when the dialog is closed.

You are right.

I believe I fixed it in 36dc3b8. Ideally, I'd just move the color picker to to the MapillaryMainDialog, but I don't have the time to do that right now.