Добавить цветную строку в TRichEdit

{ 
  To color text in a TRichEdit, follow this two steps: 
 
 
  1) Select the text with the SelStart, SelLength properties. 
 
  2) Set the text attribtutes through the SelAttributes property. 
}
 
 { 
  1. Example/ Beispiel: 
 
  Add a colored line to a TRichEdit: 
}
 
 procedure AddColoredLine(ARichEdit: TRichEdit; AText: string; AColor: TColor);
 begin
   with ARichEdit do
   begin
     SelStart := Length(Text);
     SelAttributes.Color := AColor;
     SelAttributes.Size := 8;
     SelAttributes.Name := 'MS Sans Serif';
     Lines.Add(AText);
   end;
 end;
 
 procedure TForm1.Button1Click(Sender: TObject);
 begin
   AddColoredLine(RichEdit1, 'Hallo', clRed);
   AddColoredLine(RichEdit1, 'Hallo', clGreen);
 end;
 
 { 
  2. Example/ Beispiel: 
 
  To color the 5 characters. 
  Die ersten 5 Zeichen im Richedit blau einfдrben. 
}
 
 
 procedure TForm1.Button1Click(Sender: TObject);
 begin
   RichEdit1.SelStart  := 0;
   RichEdit1.SelLength := 5;
   RichEdit1.SelAttributes.Color := clBlue;
 end;
 
 { 
  3. Example/ Beispiel: ( by www.delphimania.de) 
 
  To color a specified line with a color 
  So kann eine beliebige Zeile mit einer Farbe gefдrbt werden: 
}
 
 procedure RE_ColorLine(ARichEdit: TRichEdit; ARow: Integer; AColor: TColor);
 begin
   with ARichEdit do
   begin
     SelStart := SendMessage(Handle, EM_LINEINDEX, ARow - 1, 0);
     SelLength := Length(Lines[ARow - 1]);
     SelAttributes.Color := AColor;
     SelLength := 0;
   end;
 end;
 
 procedure TForm1.Button1Click(Sender: TObject);
 begin
   ZeileFaerben(RichEdit1, 4, clGreen);
 end;

Взято с сайта: https://www.swissdelphicenter.ch