Mikaelh said there is different colorful flickering patterns. So if you learn them - it would be possible to ID monster. Problem is - to learn this flickering patterns - we need list of this types of flickering. Something like:
1) red-grey-blue flickering. Its called R-flickering. It used by some *-monsters, for example, Jumping fireball of Perplexity. Example of flickering:

2) grey-jumping flickering. its called G-flickering. Its used by some t-monsters, for example, Monk of Drunkness. Example of flickering:
This example of course just for a jokes, but... Anyone knows some patterns? Please post all you know, lets start collecting them %)