This is about the concept of visual equilibrium. It is a reconciliation of opposing forces in a composition that results in visual stability. Most successful compositions achieve balance in one of two ways: symmetrically or asymmetrically. The contrast in colours, contrast in shapes and patterns form a balance on our living space. Creating a natural focal point such as a fireplace or highlighting a particular piece of furniture, artwork, or even simply painting a contrasting colour in one area of the wall. This creates balance.
Relating the design elements to the idea being expressed in design reinforces the principal of unity like a quiet passive subject, benefiting from horizontal lines, soft texture and less tonal contrast. For instance, selecting 3-4 colours and using them in varying shades throughout the house can unify a collection of space.
The visual effect of combining similar, related elements, like adjacent colours on the colour wheel, similar shapes etc. Adopting a harmony effect hence creates calmness, serenity and comfort to the interior design concept.
When one or more elements of the design are used repeatedly to create a feeling of organized movement, there is rhythm. Variety is essential to keep the rhythm exciting and active. Such as repeating a pattern, colour, texture, line, or other elements creates the rhythm throughout the space. Adopting this mechanism will also create a sense of movement to your space, leading the eye from one design element to another.