anchor.diff:    function Lighter(Color: TColor): TColor;
     {find a somewhat lighter color for shading purposes}
     const
  -    CF = 1.15; // CF > 1 makes color lighter
  -    CP = trunc(255 / CF);
  +    F = 1.15; // F > 1 makes color lighter
     var
  -    Red, Green, Blue, Lightest: Byte;
  -    F: single;
  +    Red, Green, Blue: Byte;
     begin
       if Color and $80000000 = $80000000 then
         Color := GetSysColor(Color and $FFFFFF)
  
positive.code:       Red := Color and $FF;
        Green := (Color and $FF00) shr 8;
        Blue := (Color and $FF0000) shr 16;
  //      Lightest := Max(Red, Max(Green, Blue));
  //      if Lightest > CP then
  //        F := 255 / Lightest
  //      else
          F := CF;
        Result := RGB(Min(255, Round(F * Red)), Min(255, Round(F * Green)), Min(255, Round(F * Blue)));
      end;
    end;
  
negative.code:       end
        else if S[I] in [bssRidge, bssGroove] then
        begin {ridge or groove}
          Bnd[0] := PO[I];
          Bnd[1] := PO[(I + 1) mod 4];
          Bnd[2] := PM[(I + 1) mod 4];
  