is Assigning Color Profiles A Permanent Action?

is it possible to change a color profile with no permanent changes in the original file?

for additional clarity:

Photoshop> Edit> ASSIGN Profile (is the move my Bruce Fraser's text was referring to)

Photoshop> Edit> CONVERT to Profile does change/degrade the color (if the conversion move is saved, the damage is permanent and cannot be recovered.  if the conversion move is not saved, the degradation still occurred in the open document, but is not permanent because it was not saved)

generally use and maintain the original embedded profile (color space) -- convert to a destination profile only as needed -- keep profile conversions to an absolute minimum because the clip or compress color information

Bruce Fraser summed this up in an Adobe forum:

"You could change profiles a thousand times via Assign Profile and the image would not degrade... inasmuch as the numbers in the file wouldn't change, this is true. But it would display incorrectly, and convert to any other space incorrectly, so it's fair to say that while the integrity of the data hasn't been compromised, and you can rescue the file by assigning the correct profile, for all practical purposes, it's hosed."

Assigning a profile does not change the original data. It does change the interpretation of that data, though, so it looks different.

Converting to a profile does change original data, so that's potentially destructive and shouldn't be done unnecessarily.