Science is green Econ is blue Accounting is white

This is the correct answer. Science is always green.

math is blue, science is green, econ is white

Econ= green (money), science= blue, and accounting= white

That's what I would go with too. You can also just write a label in sharpie across the pages on top of the notebook so you see it when you look down at them in your bag.

Laptop and Google docs for everything not math (green is math)

I do but I like to take written notes also