What is font color 'automatic' in Impress?

[jdpipe]

I wanted to ask what is meant by the color setting ‘automatic’ when editing font styles in Impress.

Since ‘automatic’ does not specify either white or black, it seems to me suggest that it might be claim to be a ‘smart’ colour, eg to know whether the background is dark or light, and adjust itself accordingly. But it doesn’t seem to do that, as far as I can tell.

So therefore I am wondering what ‘automatic’ actually means. What controls the colour that LibreOffice chooses for my font colour in this case? Can I change it somewhere?

What should I do, in general, to control font colours when working with a slide deck that includes a combination of light-background and dark-background master slides?

[mikekaganski]

It is “Black, unless the background is dark, in which case white”.

But it doesn’t seem to do that, as far as I can tell.

and this needs clarification. It indeed does just this, as far as I can tell

[EarnestAl]

The background does need to be quite dark, 80% grey hex 333333, before the font colour flips to white. Other colours vary, Dark Red 30% Hex bd0000 , or Dark Purple 20% Hex 6c00d6, seem to be the lightest shades to flip. Using palette vertical_KG.soc to test

[jdpipe]

I was editing a .pptx file which used a bitmap as the slide background. In this case, LO doesn’t seem to be clever enough to know what the background colour is, which I think is possibly a bug or at least a missing feature, since I believe the behaviour in Powerpoint is different. A solution is to edit the slide background colour in the Master slide view, in addition the use of the background bitmap.