While colour and design is subjective and personal, there are the 'golden rules' which are widely acknowledged within the interior design world.
Colour is a powerful tool in creating personalised and harmonious spaces within the home, and can greatly determine the mood of a room. For example, a rich dark navy with gold accents can make a space feel glamorous and sophisticated, while a soft, warm white can give a room a sense of openness and light.
Whether you are building or renovating, there will be limitations on some aspects of your design. Generally for interiors these are flooring and hard surfaces such as benchtops and vanities. If building or doing a complete renovation, these should be the first things chosen.
There's a frequent formula used in colour scheming - the 60-30-10 rule. Simply put, it's using the dominant colour in 60% of the room (the walls), the secondary colour in 30% of the room (flooring), and the accent colour in 10% of the room (accessories/furnishings). You don't need to take the ceiling into account unless you are painting it in a colour other than white.
Lighting plays a big part in the look and feel of a room and should always be considered. Take into account the natural light in the room and what the room is used for - kitchens and bathrooms require task lighting whereas for bedrooms and family rooms soft, ambient lighting may be more suitable.