Creating, collecting and keeping handy all your color-related stuff for stories is a lot easier if you have a notebook in which you can work and store your reference materials.
For this you'll need:
a good size, sturdy three-ring binder
a three-hole punch
a package of top-loading sheet protectors
ruled notebook paper or a spiral-bound notebook with binder holes
dividers in the basic color spectrum (optional)
ziplock bags (optional)
How you set up your notebook should be what works best for you, but I generally go with dividing sections into the color spectrum first, then keep particular color combinations in a palette section, and put my notebook paper in the very back of the binder (I also use a spiral-bound notebook that I can remove from the binder and take with me for trips to the home improvement store or wherever when I'm hunting new color ideas.)
If you collect or make color charts, store them in your sheet protectors so you can reference them without having to remove them from the notebook:
For smaller items like paint chips, swatches and other bits can go inside your sheet protectors, too. Since they're cheaper than sheet protectors I like to use ziplock bags to hold the little stuff, and punch holes in the bottom of mine like so:
My ideas, word list charts, particular story placements and all the other writing-related work I do go in my spiral-bound notebook:
If you like to be super organized you can also use color dividers (the kind with pockets can also hold your little bits, too):
Your color notebook is also a great self-teaching tool. Once a week take it out and go color hunting, as I do, to find new words, shades and descriptors to add to one particular color section. Make a habit of this, and in no time you'll have a wonderful collection of colors to use whenever you're writing.