Why isn't the color identical when PM document is converted to PDF?

Question

Hello all,
I am using PageMaker 7.  I have made a graphic file (TIFF) which has a background RGB color of full red (255, 0, 0).  I have placed it into a PageMaker document.  To increase the background area around the graphic with an identical red background that will cover the entire page, I added a large box shape and filled it with PageMaker's RGB color red (also 255, 0, 0).
So far so good - in PageMaker both colors look identical on my laptop screen, and look identical to the original color in the graphic file.  you can't tell where the graphic file and the large background box behind it are meeting.  However, on converting the PM document to a PDF file, the PageMaker red color looks distinctly darker on the screen than the red in the graphic file, when viewed in the PDF file.  I have tried lightening the PageMaker red in various ways by altering the RGB settings, but still cannot get an identical match of reds in the PDF file.  I don't wish to darken the red color in the graphic file.
The only solution I can think of is to go back to the graphic file and increase its area so that its red color will fill the entire page when placed into PageMaker.
Is there another way?
Thanks,
Roger3

Answer 1

Hi,
Thanks for your reply.  No, I haven't converted any color images from RGB to CYMK.  The original graphic file was made as RGB.  The colored box in PM7 is set to the Color Options of:
Type: Spot
Model: RGB
(R 255, G 0, B 0)
As said, in PM7 the two red objects look identical in colour tinting etc on the screen, and you can't tell the difference.  But when the doc is converted to PDF the difference is obvious.
After posting to this forum last night (Australian time), I wondered if it had something to do with dot resolution.  The graphic file is 300 dpi, whereas the red PM box is filled with color that may be at a much lower DPI, causing a dullness in the color.  I assume the PM 7 default for this can't be altered. Maybe there is a setting in Distiller that could handle this, so that the colors are equalised.
The solution I'm currently using is to remove the box (or oblong) containing PM's RGB Red, then make another graphic file which is RGB Red (either at 300 dpi or 200 dpi, either TIFF or JPG, it doesn't matter), of the same page size as the PM doc, then place it onto the page and send it to the back so that everything else sits on top of it.  When converted to PDF you now can't tell the difference between the RGB Red in both graphics.
I'm happy with the result, but it's a workaround.
Thanks,
Roger3