How do you make sure the red you scanned in, looks the same as the red you see on the monitor and the red you print? Welcome to the arcane world of color management and calibration. Some good guides are:
* "About.com":http://photography.about.com/library/weekly/aa031003e.htm. A good basic tutorial on how to set your monitor (6500 Kelvin, 2.2 gamma for web reproduction, 1.8 gamma for printing). Also that you can use an expensive colorimeter that you stick on your monitor to calibrate exactly correctly. This products an ICC file which is a lookup table that programs use to adjust so that red is exactly red on your monitor.
* PC World Australia":http://www.pcworld.idg.com.au/index.php/id;255393276;fp;2;fpid;1277378924. A great explanation of how to get the right colors under Windows XP Pro.
* "Photoblog":http://www.pcworld.idg.com.au/index.php/id;255393276;fp;2;fpid;1277378924 has a good overview in a recent post as well
* "PC World":http://www.pcworld.com/howto/article/0,aid,110070,00.asp and "Pantone Review":http://www.pcworld.com/reviews/article/0,aid,117074,00.asp and "Calibration Roundup":http://www.pcworld.com/reviews/article/0,aid,114148,pg,00.asp. They like Pantone's $100 ColorPlus for consumers that does monitor calibration in the preview give the nod to X-rite MonacoColor as the most accurate, but it costs $250.