diff --git a/components/richmemo/richmemo.pas b/components/richmemo/richmemo.pas
index 1dfb690a8..3998cfe40 100644
--- a/components/richmemo/richmemo.pas
+++ b/components/richmemo/richmemo.pas
@@ -850,6 +850,16 @@ begin
 
   if (ModifyMask = []) or (TextLength = 0) then Exit;
 
+  if TWSCustomRichMemoClass(WidgetSetClass).isInternalChange(Self, ModifyMask) then
+  begin
+    // more effecient from OS view
+    TWSCustomRichMemoClass(WidgetSetClass).SetTextAttributesInternal(Self,
+      TextStart, TextLength, ModifyMask, fnt);
+    Exit;
+  end;
+
+  // manually looping from text ranges and re-applying
+  // all the style. changing only the ones that in the mask
   i := TextStart;
   j := TextStart + TextLength;
   while i < j do begin
diff --git a/components/richmemo/win32/win32richmemo.pas b/components/richmemo/win32/win32richmemo.pas
index 9621466f4..ee89ca0d4 100644
--- a/components/richmemo/win32/win32richmemo.pas
+++ b/components/richmemo/win32/win32richmemo.pas
@@ -72,6 +72,11 @@ type
     class function CreateHandle(const AWinControl: TWinControl; const AParams: TCreateParams): HWND; override;
     class function GetTextAttributes(const AWinControl: TWinControl; TextStart: Integer;
       var Params: TIntFontParams): Boolean; override;
+
+    class function isInternalChange(const AWinControl: TWinControl; Params: TTextModifyMask): Boolean; override;
+    class procedure SetTextAttributesInternal(const AWinControl: TWinControl; TextStart, TextLen: Integer;
+      const AModifyMask: TTextModifyMask; const Params: TIntFontParams); override;
+
     class procedure SetTextAttributes(const AWinControl: TWinControl; TextStart, TextLen: Integer;
       const Params: TIntFontParams); override;
     class procedure SetHideSelection(const ACustomEdit: TCustomEdit; AHideSelection: Boolean); override;      
@@ -583,6 +588,37 @@ begin
   RichEditManager.SetEventMask(AWinControl.Handle,eventmask);
 end;
 
+class function TWin32WSCustomRichMemo.isInternalChange(
+  const AWinControl: TWinControl; Params: TTextModifyMask): Boolean;
+begin
+  Result:=True;
+end;
+
+class procedure TWin32WSCustomRichMemo.SetTextAttributesInternal(
+  const AWinControl: TWinControl; TextStart, TextLen: Integer;
+  const AModifyMask: TTextModifyMask; const Params: TIntFontParams);
+var
+  OrigStart : Integer;
+  OrigLen   : Integer;
+  eventmask : longword;
+  NeedLock  : Boolean;
+begin
+  eventmask := RichEditManager.SetEventMask(AWinControl.Handle, 0);
+  RichEditManager.GetSelection(AWinControl.Handle, OrigStart, OrigLen);
+
+  NeedLock := (OrigStart <> TextStart) or (OrigLen <> TextLen);
+  if NeedLock then begin
+    LockRedraw( TCustomRichMemo(AWinControl), AWinControl.Handle);
+    RichEditManager.SetSelection(AWinControl.Handle, TextStart, TextLen);
+    RichEditManager.SetSelectedTextStyle(AWinControl.Handle, Params, True, AModifyMask);
+    RichEditManager.SetSelection(AWinControl.Handle, OrigStart, OrigLen);
+    UnlockRedraw( TCustomRichMemo(AWinControl), AWinControl.Handle);
+  end else
+    RichEditManager.SetSelectedTextStyle(AWinControl.Handle, Params, True, AModifyMask);
+
+  RichEditManager.SetEventMask(AWinControl.Handle, eventmask);
+end;
+
 
 class procedure TWin32WSCustomRichMemo.SetHideSelection(
   const ACustomEdit: TCustomEdit; AHideSelection: Boolean);  
diff --git a/components/richmemo/win32/win32richmemoproc.pas b/components/richmemo/win32/win32richmemoproc.pas
index 34e959b3d..e4849854c 100644
--- a/components/richmemo/win32/win32richmemoproc.pas
+++ b/components/richmemo/win32/win32richmemoproc.pas
@@ -164,7 +164,8 @@ type
 
     class function GetTextLength(RichEditWnd: Handle): Integer;
     class function SetDefaultTextStyle(RichEditWnd: Handle; Params: TIntFontParams): Boolean; virtual;
-    class function SetSelectedTextStyle(RichEditWnd: Handle; Params: TIntFontParams): Boolean; virtual;
+    class function SetSelectedTextStyle(RichEditWnd: Handle; Params: TIntFontParams;
+      useMask: Boolean = false; AModifyMask: TTextModifyMask = []): Boolean; virtual;
     class function GetSelectedTextStyle(RichEditWnd: Handle; var Params: TIntFontParams): Boolean; virtual;
     class procedure SetTextUIStyle(RichEditWnd: Handle; const ui: TTextUIParam); virtual;
     class function GetTextUIStyle(RichEditWnd: Handle; var ui: TTextUIParam): Boolean; virtual;
@@ -377,7 +378,7 @@ begin
 end;
 
 class function TRichEditManager.SetSelectedTextStyle(RichEditWnd: Handle; 
-  Params: TIntFontParams): Boolean;
+  Params: TIntFontParams; useMask: Boolean; AModifyMask: TTextModifyMask): Boolean;
 var
   w : WPARAM;
   fmt : TCHARFORMAT2;
@@ -391,26 +392,36 @@ begin
     
   FillChar(fmt, sizeof(fmt), 0);
   fmt.cbSize := sizeof(fmt);
-  
-  fmt.dwMask := fmt.dwMask or CFM_COLOR;
-  fmt.crTextColor := Params.Color;
 
-  fmt.dwMask := fmt.dwMask or CFM_FACE;
-  // keep last char for Null-termination?
-  CopyStringToCharArray(Params.Name, fmt.szFaceName, LF_FACESIZE-1); 
-  
-  fmt.dwMask := fmt.dwMask or CFM_SIZE;
-  fmt.yHeight := Params.Size * TwipsInFontSize;
-  
-  fmt.dwMask := fmt.dwMask or CFM_EFFECTS or CFM_SUBSCRIPT or CFM_SUPERSCRIPT;
-  fmt.dwEffects := FontStylesToEffects(Params.Style) or VScriptPosToEffects(Params.VScriptPos);
+  if not useMask or (tmm_Color in AModifyMask) then begin
+    fmt.dwMask := fmt.dwMask or CFM_COLOR;
+    fmt.crTextColor := Params.Color;
+  end;
 
-  if Params.HasBkClr then begin
-    fmt.dwMask := fmt.dwMask or CFM_BACKCOLOR;
-    fmt.crBackColor := Params.BkColor;
-  end else begin
-    fmt.dwMask := fmt.dwMask or CFM_BACKCOLOR;
-    fmt.dwEffects := fmt.dwEffects or CFE_AUTOBACKCOLOR;
+  if not useMask or (tmm_Name in AModifyMask) then begin
+    fmt.dwMask := fmt.dwMask or CFM_FACE;
+    // keep last char for Null-termination?
+    CopyStringToCharArray(Params.Name, fmt.szFaceName, LF_FACESIZE-1);
+  end;
+
+  if not useMask or (tmm_Size in AModifyMask) then begin
+    fmt.dwMask := fmt.dwMask or CFM_SIZE;
+    fmt.yHeight := Params.Size * TwipsInFontSize;
+  end;
+
+  if not useMask or (tmm_Styles in AModifyMask) then begin
+    fmt.dwMask := fmt.dwMask or CFM_EFFECTS or CFM_SUBSCRIPT or CFM_SUPERSCRIPT;
+    fmt.dwEffects := FontStylesToEffects(Params.Style) or VScriptPosToEffects(Params.VScriptPos);
+  end;
+
+  if not useMask or (tmm_BackColor in AModifyMask) then begin
+    if Params.HasBkClr then begin
+      fmt.dwMask := fmt.dwMask or CFM_BACKCOLOR;
+      fmt.crBackColor := Params.BkColor;
+    end else begin
+      fmt.dwMask := fmt.dwMask or CFM_BACKCOLOR;
+      fmt.dwEffects := fmt.dwEffects or CFE_AUTOBACKCOLOR;
+    end;
   end;
 
   Result := SendMessage(RichEditWnd, EM_SETCHARFORMAT, w, PtrInt(@fmt))>0;
diff --git a/components/richmemo/wsrichmemo.pas b/components/richmemo/wsrichmemo.pas
index 232c808fd..093d4c690 100644
--- a/components/richmemo/wsrichmemo.pas
+++ b/components/richmemo/wsrichmemo.pas
@@ -59,6 +59,11 @@ type
     class function GetStyleRange(const AWinControl: TWinControl; TextStart: Integer; var RangeStart, RangeLen: Integer): Boolean; virtual;
     class function GetTextAttributes(const AWinControl: TWinControl; TextStart: Integer;
       var Params: TIntFontParams): Boolean; virtual;
+
+    class function isInternalChange(const AWinControl: TWinControl; Params: TTextModifyMask): Boolean; virtual;
+    class procedure SetTextAttributesInternal(const AWinControl: TWinControl; TextStart, TextLen: Integer;
+      const AModifyMask: TTextModifyMask; const Params: TIntFontParams); virtual;
+
     class procedure SetTextAttributes(const AWinControl: TWinControl; TextStart, TextLen: Integer; 
       const Params: TIntFontParams); virtual;
     class function GetParaAlignment(const AWinControl: TWinControl; TextStart: Integer;
@@ -155,9 +160,22 @@ begin
   Result := false;
 end;
 
+class function TWSCustomRichMemo.isInternalChange(
+  const AWinControl: TWinControl; Params: TTextModifyMask): Boolean;
+begin
+  Result:=false;
+end;
+
+class procedure TWSCustomRichMemo.SetTextAttributesInternal(
+  const AWinControl: TWinControl; TextStart, TextLen: Integer;
+  const AModifyMask: TTextModifyMask; const Params: TIntFontParams);
+begin
+
+end;
+
 class procedure TWSCustomRichMemo.SetTextAttributes(const AWinControl: TWinControl; 
   TextStart, TextLen: Integer;  
-  {Mask: TTextStyleMask;} const Params: TIntFontParams);
+  const Params: TIntFontParams);
 begin
 end;