What is the narrator point of view in the novel, This Is How You Lose the Time War?

The point of view of This Is How You Lose the Time War shifts frequently. About half of the novel takes place in third-person narration. Every other chapter is from the perspective of Red or Blue, respectively. Half of each chapter tends to detail a specific mission they are undertaking to make things go a certain way for their society, and the other half is a letter that they read from the other from their first-person perspective.