There are a few ways to get correct color calibration. The most widely used is what used to be called a "MacBeth" color checker, now made by X-Rite (http://www.adorama.com/DKMCC.html). X-Rite also makes a complete color checking system (http://www.adorama.com/GHCCP.html) which can automatically check and adjust your color calibration (you shoot two images exactly the same, one with the chart and one without). Of course both of these are useless without at least a little color calibration for your computer monitor so you'll need something like this (http://www.adorama.com/ICVS4X100.html).

But, to be honest 99.9% of the people looking at your images (including curators) will not have calibrated monitors so if you are making photos of your collections for the web, I wouldn't worry too much about absolutely perfect color. The nice thing about the Macbeth or the X-Rite is that they are "industry standards" so even if your own monitor isn't perfectly calibrated if you include it in any images you send off for publication, the publisher can color correct themselves.

The easiest (and cheapest) way to color correct is using the "White Balance Tool" in Camera RAW and a grey card, see this for instructions (http://www.adobe.com/digitalimag/pdf...kflow_sec3.pdf).

As for scales, I usually make my own but a quick search turned up these (http://www.crime-scene.com/store/references.shtml).

If it was up to me, and it isn't in my case, I would save unprocessed RAW files (which include a scale and color checker in the image) as your "archival" image (and the one you would send out for publishing) and make smaller JPEGs or JPEG2000s (with the scale/color checker cropped out) for public consumption.

Jason