Most people use the color squares that are provided in the paint department, rather than going to the trouble of experimenting with colors on their own. This is simply because the paint manufacturer has already done that for you, but you can experiment with colors on your own.
Mixing colors to create that special color you want requires a little testing on your part. If you are really not happy with the color squares at your local home improvement or department store. You can take the time to come up with some very pretty and special colors that will be somewhat different than people usually see on the color squares.
It is not hard at all, however, you might want to purchase a color chart and play around with the different colors of the rainbow to find out just what colors you can mix together to create the precise color you are looking for.
You do not have to spend a lot of money purchasing all the colors of the natural color chart. You can save yourself that expense by purchasing a small set of watercolors. This way you can use them to get an idea of what you want. For instance, if you add a little yellow to red, you can get orange, and by mixing a little blue, the orange will turn to a brown hue. By adding various amounts of different colors from your water colors to the red will bring about many different hues of the red.
The same idea will work for other colors such as yellow, or blue. Blue and yellow will become a hue of green and by adding some of the white, you can produce a lime green. Then to lighten or darken the hues just add a touch of the lightest or darkest color. You can come up with some very beautiful blue hues, such as a Caribbean, Aqua, Sky, Wildflower or many other blue hues. Red can produce hues from Apple, Berry, Watermelon, and others. By adding different amounts of brown, you can make a Cinnamon or maybe an Orchid hue, a little more brown and you can produce a wine color.
Once you have the idea of the color you would like to paint you can then purchase some small cans of the same colors that you have decided to use. And begin testing the colors using real paint just to see if you get the same effects.