What is the CRI (Colour Rendering Index) and why does it matter?

Colour Rendering Index (CRI) is a type term that is used to measure how accurately a light source displays colours compared to natural daylight.  It has a scale between 0 to 100.  0 being the lower and 100 being the higher and closer to a natural daylight colour.

A CRI of 80 or above is considered to be the desired standard for most general lighting applications that require a daylight colour.  This would include environments such as homes and offices.  However, for environments where colour accuracy is particularly important a CRI of 90 or higher is recommended.  This would apply to retail settings and some art galleries to give some examples.

Low CRI lighting can noticeably distort how colours appear.  It can make reds look dull or brownish; blues washed out, and skin tones can seem unnatural.  This can have a negative impact on aesthetics and functionality.  This is especially applicable in spaces where accurate colour perception is vital.

High CRI lighting on the other hand greatly helps to enhance colour vibrancy and clarity. It allows objects to appear more natural and true to life.  This improves the overall visual experience of the room the lights are being used in. This is particularly important in:

• Retail environments where product appearance can influence purchasing decisions
• Kitchens where accurate colour helps with food preparation
• Bathrooms where natural lighting is important for grooming and self care
• Creative spaces such as photography or design studios

CRI works alongside colour temperature which is measured in Kelvin e.g 4000K or 6500K. Colour temperature serves to tell us if the light appears warm white; cool white or daylight.  CRI determines how accurately colours are rendered under that light.  Both factors should be considered when choosing your lighting.  A high CRI does not necessarily mean that a bulb will be a daylight colour and this applies vice versa as well.

High CRI LEDs can be more expensive but they offer a noticeable improvement in the quality of light.  They are a worthwhile investment if you are looking for a high quality light to enhance the visual quality of the room you are looking to use the lights in.  As LED technology has advanced, many modern LED bulbs are now able to offer a high CRI without sacrificing any energy efficiency.

CRI is an essential factor in lighting quality and it is worth paying attention to if you need a high quality light.  Choosing a high CRI light source ensures that the colours in the room appear vibrant, natural, and consistent.  This contributes greatly to enhance both the functionality and appearance of your space.