How to change the color scheme of DifferentialRoot and DifferenceRoot outputs?

Question

Question:

Differential root reduce uses the font color of the stylesheet and a default white background. How to change the color of the background ?

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Why :

I am using a dark style sheet where text is written in white on a black background. However, the white font and white background of the output makes it illegible like in the image below:

Answer 1

Both DifferentialRoot and DifferenceRoot use the same template for their box structure, which is named "HolonomicDisplay".

Therefore, the styling is set by the stylesheet, which you can access with CurrentValue[{StyleDefinitions, "HolonomicDisplay"}], and also change in the usual manner of changing stylesheet. You can also set it programatically:

displayFunction = (TemplateBoxOptionsDisplayFunction /. 
     CurrentValue[{StyleDefinitions, 
       "HolonomicDisplay"}]) /. (Background -> _) -> (Background -> Yellow);

SetOptions[SelectedNotebook[], 
  StyleDefinitions -> 
   Notebook[{Cell[StyleData[StyleDefinitions -> "Default.nb"]], 
     Cell[StyleData["HolonomicDisplay"], 
      TemplateBoxOptions -> {InterpretationFunction -> (#2 &), 
        DisplayFunction -> displayFunction}]}]];

Version 13.1+

It seems that TemplateBoxOptionsDisplayFunction was changed to TemplateBoxOptions in 13.1. Therefore, you should instead use:

displayFunction = (TemplateBoxOptions /. 
     CurrentValue[{StyleDefinitions, 
       "HolonomicDisplay"}]) /. (Background -> _) -> (Background -> Yellow);