In Lightroom and other such programs, color temperature for lighting is easy with an eyedropper tool if you have a true neutral in the photo, such as a grey card. For a natural object, it gets you close enough to fiddle with, usually.
What about matching a known color that's not grey? For example, an article of clothing that can also be shot as an exemplar at another time.
There are color plaques used for photography, some quite pricy. How are they used other than by manual fiddling by eye?
Furthermore, the color temperature + tint model doesn't seem to be as effective with various indoor lighting sources, which I suppose don't have nice black-body spectra.
Is there a tool (preferably to use with Photoshop) that can do such color calebration?
Clarification: I know how to use the gray card (I prefer a cloth to get different angles at one go) in a preliminary shot (implied by mentioning the eyedrop-on-gray tool). My question is specificly how to handle not having that, and bad large-area lighting as well.