Author: Jonas Bilinkevicius

How can I find out whether the current printer is ready to print in colour, rather 
than just capable of printing in colour?

Answer:

Solve 1:

This works for some but not all printers, depending on the driver capabilities:

1   { ... }
2   var
3     Dev, Drv, Prt: array[0..255] of Char;
4     DM1: PDeviceMode;
5     DM2: PDeviceMode;
6     Sz: Integer;
7     DevM: THandle;
8   begin
9     Printer.PrinterIndex := -1;
10    Printer.GetPrinter(Dev, Drv, Prt, DevM);
11    DM1 := nil;
12    DM2 := nil;
13    Sz := DocumentProperties(0, 0, Dev, DM1^, DM2^, 0);
14    GetMem(DM1, Sz);
15    DocumentProperties(0, 0, Dev, DM1^, DM2^, DM_OUT_BUFFER);
16    if DM1^.dmColor > 1 then
17      Label1.Caption := Dev + ': Color'
18    else
19      Label1.Caption := Dev + ': Black and White';
20    if DM1^.dmFields and DM_Color <> 0 then
21      Label2.Caption := 'Printer supports color printing'
22    else
23      Label2.Caption := 'Printer does not support color printing';
24    FreeMem(DM1);
25  end;



Solve 2:

26  function IsColorPrinter: bool;
27  var
28    Device: array[0..MAX_PATH] of char;
29    Driver: array[0..MAX_PATH] of char;
30    Port: array[0..MAX_PATH] of char;
31    hDMode: THandle;
32    PDMode: PDEVMODE;
33  begin
34    result := False;
35    Printer.PrinterIndex := Printer.PrinterIndex;
36    Printer.GetPrinter(Device, Driver, Port, hDMode);
37    if hDMode <> 0 then
38    begin
39      pDMode := GlobalLock(hDMode);
40      if pDMode <> nil then
41      begin
42        if ((pDMode^.dmFields and dm_Color) = dm_Color) then
43        begin
44          result := True;
45        end;
46        GlobalUnlock(hDMode);
47      end;
48    end;
49  end;
50  
51  function SetPrinterColorMode(InColor: bool): bool;
52  var
53    Device: array[0..MAX_PATH] of char;
54    Driver: array[0..MAX_PATH] of char;
55    Port: array[0..MAX_PATH] of char;
56    hDMode: THandle;
57    PDMode: PDEVMODE;
58  begin
59    result := False;
60    Printer.PrinterIndex := Printer.PrinterIndex;
61    Printer.GetPrinter(Device, Driver, Port, hDMode);
62    if hDMode <> 0 then
63    begin
64      pDMode := GlobalLock(hDMode);
65      if pDMode <> nil then
66      begin
67        if (pDMode^.dmFields and dm_Color) = dm_Color then
68        begin
69          if (InColor) then
70          begin
71            pDMode^.dmColor := DMCOLOR_COLOR;
72          end
73          else
74          begin
75            pDMode^.dmColor := DMCOLOR_MONOCHROME;
76          end;
77          result := True;
78        end;
79        GlobalUnlock(hDMode);
80        Printer.PrinterIndex := Printer.PrinterIndex;
81      end;
82    end;
83  end;