In general, albino Burmese seem to lose red pigment as they age. So if you see super red ones like the one in the picture below - it's most likely a hatchling. It's not certain why this color change occurs. It could be due to changes in nutrients available from their diet, hormonal changes as they go through life stages or some other unknown factor.

What ever the cause, it seems to be a very predictable occurance, and while some snakes retain some of the orange pigment for longer than others - most become almost completely yellow by the time they're 4 or 5 years old. This can happen earlier or later - probably multi-factorial (diet to hormones to genetics to environment etc...)

Another reason snakes can appear different is changes in the wavelength of light hitting their skin - a snake will look much different in natural sunlight versus incandescant or even flourescent lighting. A camera's flash will often distort colors from how they appear to the naked eye as well, and each camera and camera setting may also cause the variations you'll see here and other places on the internet.