what to keep in mind is that colori / spectrophotometer use different gelatin color filters that ages with time and these must be kept dark.
I have no idea what you're referring to, especially if you're referring to the i1 Pro, Spectrolino / Spectroscan, DTP line, and similar spectrophotometers.
It's true that for ISO 9000 compliance you need to have the devices re-certified every couple years (or whatever), but I very much doubt there are any gelatin filters in any of them -- and, if there are any, they're certainly not ever exposed to ambient light.
Mostly, it's the bulbs that change with usage, and recertification writes new values to the firmware to match the new spectral characteristics of the bulb.
And, honestly? Unless you're doing ISO 9000 certification or you have good reason to suspect the performance of your instrument, recertification is a waste. These are quality instruments that are built to last, and they do.
Cheers,
b&