Colour theory in fashion means studying how colours mix and what effect different colour combinations have. By understanding how colours work together, such as in complementary, analogous, or monochromatic schemes, you can create stylish and harmonious looks that are visually appealing.

Colour Wheel Basics

Primary Colors: Red, Yellow, and Blue. These are the fundamental colours from which other colours are made.

Secondary Colors: Orange, Green, and Purple. These colours are created by mixing 2 primary colours.

Tertiary Colors: These are the colours created by mixing primary and secondary colours.

Colour Schemes

1. Monochromatic: A monochromatic colour scheme involves various shades, hues and tints of the same colour making the outfit look aesthetically pleasing. This application stresses contrast and depth of the colour range to create a harmonious design.
   Example: All shaded to red, from light red to cherry red.
   
2. Analogous: Analogous colours are the colours that sit next to each other on the colour wheel. This approach helps use shades with the same hues, like red, yellow, and orange. This scheme is also used in nature and can blend the outfit to create a cohesive look.
   Example: Yellow, yellow-green and green.
   
3. Complementary: Complementary colours are those that sit opposite to each other on the colour wheel, like red and green, blue and orange, and yellow and purple. These are known for their bright and vibrant colours. These colours can draw attention and can make your outfit stand out.
   
4. Triadic: Triadic colours are the colours that are uniformly spaced around the colour wheel. This arrangement of colours creates a balanced and harmonious look and can create a lively and durable look. Triadic colours are used in art, design and branding as they can create a look that can be made appealing yet balanced with stability.
   Example: Red, yellow and blue.
   
   5. Split-Complementary: Split-complementary colour scheme uses one base colour as its main and two colours next to its opposite on the colour wheel.
           Example: Blue, yellow-orange and red-orange.

Tips for Mixing and Matching Colors

• Start with a Neutral Base: Neutral colours like black, grey, beige and white are the basic colours that can be combined with any colour and create a balanced, stylish, casual and formal look.
  
• The 60-30-10 Rule: This rule can make an outfit balanced. 60% should be a dominant colour. 30% should be a secondary colour and 10% should be an accent colour to enhance the outfit with a pop of colour.
  
• Experiment and Have Fun: Experiment and have fun with the colours. Fashion is about expressing your unique style and feeling confident.
  
• Consider Your Skin Tone: Consider your skin tone while choosing your colour as some might enhance your natural glow and some might not complement you.
  

Dress for the Occasion: Consider the formality of an event and choose the colours accordingly.

By understanding the colour theory, you can create the outfit according to the vibe, occasion and formality. Remember to stay confident and experiment with your style to feel the inner sense of satisfaction.