From my experience, I'd say not always. If you're trying to match colors
from one store to the next you could be in for some surprise. Even within
the same store, you don't know under what light they took the photos.
One of the disadvantages of arm-chair shopping. :-(
That's one of the reasons I prefer to buy (pre-cuts) such as jelly rolls,
charm packs, etc from the same collection. At least I know they will match. :D