There's nothing wrong with making a color mistake. In fact, seeing what doesn't work, for whatever reason, is the best way to train your eye and learn what does work, and what you like to live with. Paint is the all time champion of decorating bargains, so it's a very inexpensive lesson, especially when compared with the cost of a couch. If you paint a room blue, only to realize that with a northern exposure, blue walls make the room feel cold, you'll learn from it and apply the lesson to future projects.
To reduce the cost of your experiments, buy the color(s) you're considering in the sample size offered by many paint manufacturers. It's just enough paint to apply two coats on a 2x3 foot piece of foam core so that you can view the color all around the room under varying light conditions. It also avoids the misleading color impression from the common mistake of painting swatches side by side on the walls.
So don't be reluctant to try new colors. You can make mistakes on a small, inexpensive scale, encourage your creative instincts, learn a lot, have a wonderful time in the process and best of all, wind up with colors you really like.