It appears that the THTMLTreeView is not honoring the node selection color of the current VCL Theme so I find I have to do this:
tv.SelectionColors.BorderColor := TStyleManager.ActiveStyle.GetSystemColor(clHighlight);
tv.SelectionColors.ColorFrom := TStyleManager.ActiveStyle.GetSystemColor(clHighlight);
tv.SelectionNFColor := TStyleManager.ActiveStyle.GetSystemColor(clHighlight);
tv.SelectionFontColor := TStyleManager.ActiveStyle.GetSystemColor(clHighlightText);
tv.SelectionNFFontColor := TStyleManager.ActiveStyle.GetSystemColor(clHighlightText);
These are the colors as set in the IDE, but they are not translating to the respective theme colors unless I set them manually in code to the same ones as above.
THTMLTreeView version 1.4.2.0
Delphi RIO 10.3