Darker theme doesn't invert colors in the document to fully black, however Light theme does. Why?

[student13371]

Action number 1:
SumatraPDF > Settings > Theme > Light
Press keyboard key I to invert colors in the document.

Outcome of Action number 1:
Page background is fully black.
Please see the image below for illustration (note fully black background):

Action number 2:
SumatraPDF > Settings > Theme > Darker
Press keyboard key I to invert colors in the document.

Outcome of Action number 1:
Page background is NOT fully black, but grey in color.
Please see the image below for illustration (note grey background):

Is it possible to make Darker theme when inverting colors in the document to show page background fully black the same way as White theme does when colors are inverted?

[GitHubRulesOK]

With Darkest in pre-release and inverted it will be as dark as this

At a distance the inversion will affect the text appearance

[student13371]

Dear GitHubRulesOK,

I have just installed the Latest SumatraPDF pre-release build version 16779 and SumatraPDF > Settings > Theme > Set theme 'Dark' achieves the same fully dark background on inversion as Light theme.

Thank you!