I need help finding an anime i forgot the name of.

The anime is about two girls who i think are robots but i forgot. So because they are robots they live for a long time and time after time they change their appearance but there main colors are red and blue (i think). These two girls work for an organization who have other robots(i think again). So their job in the organization is they go on these space ship things and fight in a space like place. Also there is a second season about those two girl's kouhai. And the two girls come out in the second season too but in different appearances. And if possible could you show me a photo of those two? Please i really wanna find that episode!!!