In order to create the perfect guest bedroom, you can focus on using colours that are calming and soothing so that your guests can relax completely. However, it's important to keep your décor theme in mind and opt for colours that fit well with the theme. For instance, if you have a modern guest room design theme, a balance between statement colours and muted hues is what you should aim for. A neutral colour palette like white, beige or cream will look elegant and minimal while also laying the foundation of the guest room interior design. You can match the bedding to this aesthetic by keeping it white or pastel green. If you are a fan of colourful interiors and don't want to go with neutrals, picking bright colours can be a great option as it would add just the touch of colour your guest bedroom needs.