Terrorist Snake

Why would a poisonous snake need to blend in? It has poison to protect him or her, right? That has been the theory, anyway. Snakes with poison usually have bright colors or rattles or something to warn competitors or predators. They don't need camo to protect themselves.

A newly discovered snake in Borneo is a chameleon and is poisonous. Now, aside from terrorizing it's prey and predators, too, by blending in and then striking, what evolutionary purpose would such traits confer?

Maybe it just doesn't like being found by nosey scientists. And how would we know if it is so rare? I'm guessing the snake blends in everywhere it's in the water. The scientists wouldn't even know that the "reed" is a snake and poisonous and blending in.....

Unlike the chameleon, it is presumably not changing colour for camouflage.

Really, we can presume this?