The string "Background" (null context) is used in several places:

These refer to the layer name:

- libs/image/kis_image.cc:686
- plugins/impex/psd/psd_loader.cpp:162
- plugins/python/comics_project_management_tools/comics_template_dialog.py:302
- libs/ui/forms/wdgnewimage.ui:484 ("Background:")

These refer to the colour:

- plugins/paintops/defaultpaintops/brush/kis_brushop_settings_widget.cpp:69
- plugins/filters/halftone/KisHalftoneConfigPageWidget.ui:175 ("Background:")
- plugins/generators/screentone/KisScreentoneConfigWidget.ui:394 ("Background:")

The following instances of "Background" also refer to the layer name, but with context:

- plugins/impex/psd/psd_layer_section.cpp:298 (context: "Automatically created layer name when saving into PSD")
- plugins/tools/svgtexttool/SvgTextTool.action:33 (context: "action")
- libs/image/KisTranslateLayerNamesVisitor.cpp:56 (context: "Layer name for translation of template")

In addition, there are instances of untranslated "Background" being used for layer names:

- libs/ui/KisDocument.cpp:2301
- libs/ui/KisDocument.cpp:2308 ("Background Fill", though this instance may also be interpreted as "background color" without issue)


My take on this:

- I tend to think that it is better to just write "background color" when referring to the colour, unless there really is a space limitation, in which case it should be clearly stated in the context string.
- We should try to consolidate all usages of layer names. It seems that reusing `libs/image/KisTranslateLayerNamesVisitor.cpp:56` is a good solution, even though it may not seem to be exactly for the purpose.
- "Background Fill" is the odd one out because there is no existing l10n string for it, which means we may need an exception to the string freeze to have it translated properly.