[update: Panorama Tools 2.6b1 has a color correction feature, see below]

1. Reduce color difference in your original images: Make sure you shoot with fixed exposure settings. For digital cameras also lock the white balance settings. Set the white balance to 'manual', even the preset white balance settings on some cameras give variation across images. If you shoot on film: don't scan the prints, but instead use a film scanner to scan the negatives directly. Even then, almost all film scanner software always performs some auto-exposure correction for each individual frame, even if you lock the software's exposure settings. Try VueScan (www.hamrick.com), which gives you complete control over your scanner's exposure settings.

2. Create a layered Photoshop file of your panorama. In Photoshop you can adjust the color balance and correct levels of each inidividual image.

3. Increase the feather width. This results in a smoother overlap, which makes the color difference less noticable. The drawback of a large feather width is that small alignment errors will become more visible as 'ghost images'.

Hope this helps!
Joost
2002-Feb-12 10:31 address-suppressed

I use an LS1000, with the NikonScan software. There's a "pre-scan" feature 
in my version of NikonScan, which I make sure is OFF when I'm scanning a 
set of images that make up one panorama.

Here's my process:
- Scan first image, with pre-scan turned on
- Adjust color/contrast/focus for the first
   image using the NikonScan tools
- Turn off the "pre-scan" feature
- Do a "final" scan of the first image
- Scan the rest of the images

I usually do a "preview" of each image, for cropping, etc. before I do a 
"final" scan. The important thing is to make sure that "pre-scan" is off. 
NikonScan will complain about "pre-scan" being off, and you'll need to tell 
it to ignore and scan anyway.

Hope this is useful...

Greg

Since version 2.6b1, Panorama Tools can perform color correction too!

For more information:
http://www.fh-furtwangen.de/~dersch/cbcorrect/cb.html