Getting your bulb colour wrong is not only annoying but also means more hassle in returning products. This may even potentially be at your own expense. The alternative is putting up with a colour temperature which is wrong for the room it’s being used in. For retail properties, the wrong lighting can even effect how your product is viewed.

Getting it right the first time is important – ‘white’ does not mean ‘white’!

This article provides some basic principles on colour temperature, including our tips and product recommendations for choosing some of the best bulbs around for your home or business.

In this guide:

• Learn the basics of colour temperature including some key facts we think you need to know.
• Find out why the Colour Render Index (CRI) is important to note especially in retail settings.
• Identify which areas of the home each type of colour temperature best suits.
• Read our product recommendations for Extra Warm White, Warm White, Cool White & Daylight GU10s.
• Discover why we think shopping with us is beneficial for you as a customer.

Colour Temperature Explained

When it comes to energy-efficient dimmable LED GU10 spotlights, colour temperature means the colour of your light output. Colour temperature values range from warm amber to icy blue. These values include extra-warm white, cool white, and daylight.

The full term, correlated colour temperature or CCT, is usually shortened to colour temperature. Colour temperature is measured in Kelvins.

A Kelvin (K) is the unit used to measure a light bulb’s colour temperature. Colours below 3000k are considered warm, while those above 4500k are considered cool. The simple chart below is a great way to visualize the colour output you can expect based on its Kelvin value.

The Kelvin Temperature Scale

Published under Creative Commons License. https://creativecommons.org/licenses/by-sa/4.0

Some key facts to consider:

1. For the best results when buying dimming LED GU10s, keep in mind that there may be slight discrepancies between the manufacturer’s description and the actual colour temperature. It’s best to check the Kelvin value rather than the label.
2. Many brands describe their 3000k LED GU10 spotlight bulbs as warm-white, the colour usually attributed to traditional halogen lamps. This is inaccurate.
3. The closest match to your regular halogen is actually a 2700k LED GU10 spotlight bulb, even though most manufacturers describe it as extra-warm white.
4. The top three colour temperatures are 2700k for extra-warm white, 3000k for warm white, and 4000k for cool white.
5. The higher you go up the Kelvin scale, the harsher and more bluish the white colour gets. The lower you go, the warmer it is.

What is the Colour-rendering Index?

The colour-rendering index or CRI measures the effectiveness of a dimmable LED GU10 spotlight in rendering the true colours in your home or business.

On a scale from zero to 100, the higher you go, the more accurately your LED GU10 will render colours (and mimic sunlight itself).

A low CRI can make similar colours hard to distinguish or give a dull tinge to colours making them a really bad fit where colour rendering is vital – for example clothing and retail stores, car showrooms etc. In these environments, it is essential to pick spotlights with very high ratings.

LED Spotlights with a CRI lower than 80% should be avoided.

Reputable high-quality brands like Philips will list the CRI on the package. Excellent LED spotlights, like the Philips Master 5.5w LED GU10 36° - 940 and the Philips Master 5.5w LED GU10 36° - 927, come with a CRI of 97% making them the best around when it comes to colour output.

Both Sylvania and Osram also offer professional ranges with CRI of 90 and above.

Colour Temperatures: Where to Use in the Home

Colour Temperatures: Our Product Suggestions

2700K

Extra-Warm White

The extra-warm white of 2700k bulbs is the most similar hue to the well-known soft amber of traditional halogen lamps.

Osram offers three dimmable versions under £5, a 3.1w bulb, a 4.9 bulb, and a 8w bulb. They also make non-dimmable extra-warm white LEDs under £5, like the 6.9 GU10.

Philips makes a dimmable 4.9w bulb just under £5. It’s slightly more expensive, with the 3.7w bulb under £10, and it can be dimmed all the way down to 2200.

Unlike the previous clear-finish products, Philips makes a white dimmable CorePro 5w mains voltage GU10 for under £5.

Extra Warm White Featured Product: Osram 8.3w LED GU10 36° 2700k Dimmable

This Osram GU10 has been one of our bestselling GU10’s over the past few years.

Read our Osram GU10 lighting guide for more information on this supplier.

3000k

Warm White

At 3000k LED GU10 spotlights give a warm white light, slightly brighter than their 2700k counterparts.

Most dimmable 3000k warm-white LED GU10s come as a 5w or a 5.5w bulb. These include two under £3, a clear-finish 5w bulb by Philips and a white 5w bulb by Sylvania.

Also available are two clear-finish lamps, a 5.5w bulb by Osram and a 5.5w bulb by Energizer.

Osram also offers a white 6.9w er £5. In addition to the non-dimmable warm-white LED GU10s, which are available for under £3. You can check out the clear-finish 4.3 LED GU10, it’s a remarkable light.

Warm White Featured Product: Sylvania 5w LED GU10 36° 3000k Non-Dimmable

This Sylvania GU10 has been one of our bestselling GU10’s over the past few years.

Read our Sylvania GU10 lighting guide for more information on this supplier.

4000k

Cool White

Typically 4000k LED GU10s give a cool white light similar to fluorescent lights.

Most 4000k bulbs come in 5-5.5 wattages. Sylvania makes a white 5w bulb that’s under £3. You can also choose from three lamps under £5, a clear-finish 5.5w bulb by Energizer, a white 5.5w bulb by GE, and a 5.5w bulb by Osram in a cool white finish.

If you like the unique quality of Philips, they make a slightly pricier clear-finish 5.5w bulb for just under £10.

Dimmable 4000k bulbs also come in various other wattages under £5, such as this white 3.5w bulb by GE and two clear-finish lamps by Osram, a 4.3w bulb and a 5.5w bulb. Osram also makes this clear-finish 8w bulb for just over £5.

They’re also available as non-dimmable LEDs, such as this white 5w GU10 by Sylvania and this clear-finish 4.3w GU10 by Osram, both of which are under £3.

Cool White Featured Product: Osram 8.3w LED Par16 60deg GU10 4000k Dimmable

This Osram GU10 has been one of our bestselling GU10’s over the past few years. Read our Osram GU10 lighting guide for more information on this supplier.

6000k +

Daylight

Lamps above 6000k give a crisp, super bright bluish-white light. It’s similar to natural daylight but is too harsh for general use as a residential light. The Daylight colour temperature is fantastic for alertness and attention to detail. Great for retail and factory environments, and complimentary to CCTV when used for external lighting.

Sylvania makes a £2.60 dimmable white 4.5w bulb with a colour temperature of 6500k. Energizer makes a £2.84 non-dimmable white 5.8 LED GU10 with a colour temperature of 6500k as well.

Daylight Featured Product: JCB 5w LED GU10 100° 6500K

Ideal for commercial settings and as a purpose-built task lighting in domestic kitchens and garages. The features product has proven to be a customer favourite, delivered by the reliable brand of JCB

• Designed to improve lighting in areas of the kitchen where attention to detail is needed.
• Excellent bulb at good price. Very happy.
• JCB is very reliable as a brand and is a proven favourite of customers.
• High lumen output of 370.
• Replaces a 50w halogen GU10 giving you a 85% energy saving.
• Wide beam angle of 100° meaning it’s a great choice for commercial kitchens and retail environments.
• Gives your products a genuine WOW factor.
  
  Buy 12 and save 23%  - Buy 24 and save 33%

Further Help & Advice

LED kitchen lights: planning and fitting the right lights

https://www.lampshoponline.com/advice/led-kitchen-lights

Dining room lights: types, ideas and the best lights available

https://www.lampshoponline.com/advice/dining-room-lights-types-ideas

Children’s bedroom lighting: types, planning and ideas

https://www.lampshoponline.com/advice/children-bedroom-lighting

Bedroom lighting: considerations, mood lighting and LED lights

https://www.lampshoponline.com/advice/led-lights-bedroom

Understanding Colour Temperatures

https://www.lampshoponline.com/advice/guide-led-colour-temperatures

IP Ratings for LED Lights

https://www.lampshoponline.com/advice/ip-ratings-led-lights

Choosing GU10 Bulbs – Dimmer Switches, Prices & Brands

https://www.lampshoponline.com/advice/how-to-choose-right-gu10-leds

Expert Contributors

“I do get a bit nervous about colour temperatures so I generally prefer the flexibility of a GU-10 cap so I can remove and replace lamps if the colour temperature isn't quite right for the colouration of a scheme”

Danielle Lee, DCL Interior Design

https://www.instagram.com/danilee_dcl/

“Always check what type of lighting you’d like as not all whites are created equal. We tend to go for warmer whites for homes as it adds warmth to a space.”

Tarryn Manley, Senior Interior Designer

https://miakarlsson.co.uk/