Pure or Green
Seeing the battle robots from the Traveller centre in a place like this was surprising for the two girls. Because they were mainly used for two things, one was the example used earlier for the testing, and the other for fights and battles when in war and such. Right now since they weren't exactly in the Travel centre and ended up in their room, they were pretty sure they were here to hurt them.
The A.I robots were an improvement upon the manned Mechs that used to be used.
The mechs themselves needed crystals to power them, yet no matter what level of crystal was used, the power they could produce was the same. A higher tier crystal would only allow one to use the Mech for a more extended period.