Why is my urine a brownish/redish color?

Ive been working a lot recently, drinking a lot of coffee not a lot of water. Like 2 days ago i noticed my urine was a really dark color, looked almost like Iced Tea. Last night i went out for a night of drinking with friends and noticed after i broke the seal it started clearing up, i just woke up and urinated and its back to this dark brownish color. What do i do?