The protective force field of the Giant Skru Base was initially a deep grey, giving off a metallic sheen while also overlaid with a grid of lightning stripes. It looked particularly cool and futuristic.
From outside the force field, the surveillance devices of the Blue Star humans couldn't detect what was happening inside the shield.
Yet, the video images passed on by Xue Wenli showed that the Skru had somehow turned the force field into a colorless and transparent state, making it look like a transparent water curtain.
Through this "water curtain", Blue Star humans could clearly see the situation inside merely with the naked eye.
Clearly, this was deliberately done by the Skru, intending to let the Blue Star humans know what was happening.
North America — Alaska Range — Giant Spring Eye of Mount McKinley.
The water curtain of Mt. McKinley's spring eye also turned from deep grey to a colorless and transparent state.