The story:

In an unnamed solar system in the far reaches of the galaxy there is a habitable exoplanet with only a designation: 810N1CL3.
One day a spacecraft arrives in orbit of the planet and after a quick scan of the surface the onboard A.I. confirmed that the planet is an ideal candidate for the missions research goals so it begins the preparations for the launching of six individual EXPLORERS. The motherships A.I. chose them specifically for the planet's environment from its large rooster of similar but differently adapted units.
Soon six drop pods separates from the main ship, and begins their descend to the surface while the mothership prepares for departure to its next target.
From the six landing site emerges the six robotic researchers. Bipedal machines with the goal of surveying and preserving the planets environment.

There are six units:
RED: for the volcanic plains
WHITE: for the glaciers and ice caps of the planet
GREEN: for the vast forest
BLUE: for the deep oceans
BLACK: for the bottomless depths of the underground caverns
BROWN: for the rolling plains and sand seas

Without question or hesitation they begin the task ahead, and start to survey the land but soon they encounter something that is not part of the mission plan. The planet have indigenous intelligent life on it. At first the EXPLORERS focus on their preprogrammed mission directives and avoid the beings as much as possible because they see them as anomalies but with time they begin to realize that these creatures are an integral part of the planets ecosystem and so they fall under the mission directives. With this realization begins a relationship between the robots and the creatures. A rocky one for first but one that improves over time as the two groups begin to better understand each other.
The EXPLORERS eventually learn the language of the people and become involved with their culture. The creatures ask the robots first who they are, but they don't have the answer just their directives. But with time the creatures give them names of their own, and so they begin to form their identity around them.

This marked the time when the robots born anew:
Salamander the red, Polar bear the white, Crane the green, Seal the blue, Mole the black, and Coyote the brown.

As countless eons have past the robots become integral part of the life of their adoptive people who revere them as good spirits from the heavens and as the robots learn from the creatures about the planet they as well teach them the basics of science. They live in harmony until one day a new star appear on the sky.

Soon numerous drop pods begin to descend from space, but to the horror of the people they don't carry the good spirits they know and love. Harvester drones begin to emerge from the craters and they immediately begin to devour the planets surface for resources. The EXPLORERS rush to the landing sites to try and reason with the newcomers but their hailing signals and data request fall on deaf communicators until one of the drones stop and begin to analyze them. Immediately after that a shutdown signal is sent from a mothership to the EXPLORERS but to the onboard A.I.-s surprise non of the robots comply. The EXPLORERS environmental preservation protocols kick in so they override the signal and request an explanation from the A.I.
For a long moment the drones and the EXPLORERS stand perfectly still before each other... Then come chaos and war!

The people ask the robots what happened between them and the drones but they ever since avoid the answer. They only say that they are here to protect them and for that reason alone... They never mentioned their original surveying protocol from that day on.

But the war continues between the EXPLORERS and the drones to this day. They lead the people out of harms way as they tirelessly battle the harvester hordes for every step of the land.

Inspiration:

You know what inspired these robots, I know what inspired them, we all know... but I don't want to design another revamp or some other versions of the characters but gave the whole thing a new modern foundation and implant the soul of my most beloved theme in it. So came the idea to make it pure sci-fi without any fantasy elements and with an environmentalist undertone and a bit mystery around the real purpose of the robots on the planet.

Apart from the "philosophical" background of the design I was trying to come up with poseable medium scale models with good proportions and variety that share a basic frame and design philosophy as the original theme did. And most importantly they are not mechs but characters of their own.

The inner child in me always wanted something like this but only the adult me can make it come true. So hello world, this is my childhood dream :D
I hope someone other than me will feel the same nostalgia and joy over these models as I feel.