Considerations
Many of the war plans are extremely unlikely, considering the state of international relations in the 1920s, and it was entirely within keeping with the military planning of other nation states. Often, junior military officers were given the task of updating each plan to keep them trained and busy (this was especially true in the case of War Plan Crimson, the invasion of Canada). Some colors of the war plans changed over time with new revisions, possibly resulting in confusion.
Interestingly, although the US had fought its most recent war against Germany and would fight another within twenty years, intense domestic pressure emerged for the Army to halt when it became known that the Army was constructing a plan for a war with Germany; isolationists opposed any consideration of involvement in a future European conflict. This may have encouraged the Army to focus on more speculative scenarios for planning exercises.
Read more about this topic: United States Color-coded War Plans