How to change the symbol and color the Tab in AvalonEdit

Question

How to change the symbol and color the Tab character

would like to change the character to the arrow character →

and set the red color

Answer 1

For change color the Tab character

textEditor.TextArea.TextView.NonPrintableCharacterBrush = Brushes.Red;

Answer 2

If you look at the source, you'll see that the character used to display a tab is hard coded:

https://github.com/icsharpcode/AvalonEdit/blob/106b31efe17a4992e1c02ee5c8650bc86591aeb7/ICSharpCode.AvalonEdit/Rendering/SingleCharacterElementGenerator.cs#L106