Use fastener folders with two-ply tabs to color-code by the type of document you file. Folders offer the added convenience of installed fasteners. Each folder has two fasteners.

Business Source Colored 2-Ply Tab Fastener Folders - Letter - 8 1/2" x 11" Sheet Size - 2 Fastener(s) - End Tab Location - Blue - Recycled - 50 / Box