Home design has some time honored rules, but that doesn't mean you have to follow them all. What looks good may not necessarily be comfortable and calming for a good night's sleep. In fact, breaking the rules may make your bedroom a more comfortable, inviting and healthier environment for sleep.Your bedroom should be a space where you can relax, rest and drift off to sleep, and design can make more of a difference than you might think. You may want to rethink some of the bedroom design rules that you once thought were iron-clad. Think Again on These Rules of Bedroom DesignSmall rooms don't have to be white. While neutrals are a good choice, think outside the basic color palette. Although it's not really a color, white can be reflective and somewhat exciting, and that's not what you want when you're trying to sleep. Instead of white, consider pastels and light earth tones. Blue is an especially good choice of wall color for a bedroom as it can promote feelings of calmness. You don't need to match your bed size to the room. Though you should be careful not to overwhelm your space with a huge bed you can't walk around, you can error on the side of large in the name of comfort. Having a mattress that's large enough to accommodate you and anyone you share your bed with is essential for a good night's sleep. Otherwise, you may get too hot or feel like you can't spread out at night.Don't let the light in. A light and airy bedroom looks great in magazines (and during the daytime), but at night, what you really need is darkness to get a good nights sleep. You can strike a happy medium on light by doing what hotels do: Install light curtains underneath dark blackout curtains. During the day, you can pull back the blackout curtains and let some light in. At night, close the blackout curtains so you can sleep in darkness, which supports a healthy circadian rhythm.Avoid excessive bedroom lighting. Again, light can be problematic for sleep. Good lighting is inviting and illuminates the room so you can see well. But too much light spells trouble for sleep. Look for lighting that can be dimmed at night, and opt for lighting that points down out of your eye line, like a soft lamp on a bedside table.Don't mix bold prints and patterns. Bold prints and patterns can be visually appealing and stimulating, but stimulating design isn't good for sleep. Instead, you want your bedroom to be calm and comfortable. Avoid mixing prints and make any prints and patterns in your bedroom minimal and not extremely busy.A well designed bedroom can make a difference in the quality of your sleep. Although visual appeal is important in bedroom design, so is rest. Make sure you're supporting a healthy night's sleep with good bedroom design.Amy HighlandAmy is a sleep expert at SleepHelp.org. She loves taking naps during thunderstorms and cuddling up with a blanket, book, and cats.