Cobalt:
He is named after the chemical element cobalt and its distinctive ground up powder's blue. He was named Cobalt because of a theoretical nuclear weapon that when detonated,used Cobalt to make the whole world deadly radioactive.

Waverly:
Her name means meadow of quivering aspens. She is named this since its the exact opposite of her character and personality.

Echo:
I named this since it is a name enshrined for one of the warrior cars I really like,Echosong. Echosong is a Medicine cat,which,like Echo,interpret Prophecys.

Daley:
His name can mean both assembly or valley. He is named for the sheer extremes of noise there,which is his main sense he depends on.

Matryoshka:
Her name means Little Matron,and is derived from the names Matroyna and Matryosha. She is named this since it reflects her strong personality and her mother like behavior.

And that's it!