This chart is an excellent resource to have on hand. It is great for learning how the various colors in your own palette mix and react with each other. It also shows you the numerous colors you can create at a glance. I have created one of these charts for each of my palettes.
On a quarter sheet of watercolor paper (11 x 15") you can easily create a chart for 10 to 14 colors. Count the number of colors in your palette and create a grid that has one extra square across and down. If you have 10 colors in your palette you want your grid to be 11 squares across and 11 squares down. Place an X in the top left square, this square will remain blank. Outside the grid label each color in either rainbow order or the order you have them on your palette starting with the second block. Place a swash of clean color next to the coordinating names. Then mix each color evenly on your palette with each of the other colors and place them accordingly on the grid.
Remember the game Battleship? Plot your course in a similar fashion.
For a 10 color palette, I created a grid 8.25" x 8.25" of 3/4" squares 11 across and 11 squares down. I drew 2" lines for the names of colors. All done in pencil. I also added the brand name of the paint and the type of paper to the bottom corner. I used a 1/2" flat wash brush to mix and paint the colors into the grid. For the 14 color palette, I created a grid 7.5" x 14.75" with the squares being 1/2" high by 3/4" wide.