First it starts off with a 100% of the same guinea pigs but dark guinea pigs. Then appears the very light ones that doesn't seem to blend in very well. Now here comes the predators hiding waiting for the right moment to attack the guinea pigs.
Out the predators come and attacks the guinea pigs.
But the predators only took the light guinea pigs and the reason for that is because the dark guinea pigs was able to blend to the ground since it has the same color. The light guinea pigs wasn't camouflaging with the ground so it was easy for the predators to attack the light guinea pigs an not see the dark guinea pigs.
However, since the environment has change as you can see the light guinea pigs are now camouflaging with the ground and now has a better chance of not being the target to the predators. But it's now different for the dark guinea pigs, they don't blend with the ground.
Now here comes the predators coming and now attacking the dark guinea pigs because that's the only visible thing they can see.