As a freelance designer, I often work with several different clients at once, and so I like to choose a color to represent each client (often one which matches a color used in their branding). When outlining a project on bristol board as I often do, I might use a colored marker I've associated with a client for headings, or quick fills in mock up sketches, to ensure I can easily spot notes for a specific project or task amongst a pile of others. In setting up a calendar to manage tasks for a specific project, I would again choose a color I can easily associate with the client for quick reference of my schedule through the day.
Outside of a professional workflow, color coding can also be useful for managing tasks around your home. For delegating chores to your kids, or for organizing between you and your significant other, have each member of your househeld pick a favorite color. Use these colors to create color coded Google calendars to outline and share schedules between each other. Match those colors up with sticky notes and whiteboard markers so each member can make their mark in the real world, sharing easily recognizable color coded messages with each other in a shared space.
Color can also be helpful for managing diet or exercise. Schedule your meals and fitness regiment using a bright color in your online calendar. Leave sticky notes for yourself using a matching color on the fridge or on those cookies in the cupboard for a quick reminder (via color association) of your plan for personal wellbeing.
Adding a splash of color to your organizational workflow helps bring an eye-catching visual component to task management, but it also helps to beautify and personalize the tools we use to organize ourselves. Maintaining consistency is key, as is choosing colors that have meaning to you in the different facets of your life. Simple associations work great, for example using green for finances or red for things that are high priority. As does picking less obvious associations — for example, you might have a favorite supermarket you like to shop at with a bright purple sign, in which case purple might work well as a color for a quick reminder to pick up a loaf of bread on the way home from work.
Remember to keep things simple; if you find a set of sticky notes that only come in a few colors, try to limit the catorgories used in your calendar to those colors. This will help you stick to a simple system of organization that is easy to maintain, and quick to reference using just a few bright colors to simply outline how you manage your time.
(Images: Sean Rioux)