Dontcha just LOVE color? It's a wonderful thing...and this prompt is as easy as they come. All you have to do today is get out various colors in your favorite medium, whether it be acrylics, pastels, watercolors, oil pastels, gel pens, etc. Then make a color chart of those colors. I've included a sample of my own here. (These are Caran d'Ache Neocolor II crayons. Not only did I want to show the color as it's originally laid on the page, but also when water is added.)
You can really do all kinds of things with this. If you want to make circles of the colors horizontally across a spread, then doodle around them, adding petals to make them into flowers, or even make the petals the various colors, or make a rainbow page out of your colors. The purpose for this is to have a record of your colors (make sure to label them: you can write the names out or stamp the names, or even use a label maker). It helps when you're looking for a certain color. It also inspires. It's like looking at a candy store window. I feel this way when I go into a yarn shop. Inspired by all the colors. Everything looks so yummy. Also when I go into an art supply store. Look at all of the ink bottles lined up next to each other, or the colored pencils in their displays. Makes the colors look even more edible...
Have fun with it! You might even see new color combos on the page to use in the future when you're done.