A calm contemporary living room at night, lit by soft indirect and accent light
MINALOX · DualWhite 1800–4500 K

Beyond colour temperature

Better lighting isn’t about reaching higher numbers. It’s about creating the right light for every moment.

Explore the light
Not all kelvins are created equal

200 K can make a difference.

Especially when the light gets warmer.

At very warm colour temperatures, a small numerical step can noticeably change the mood of a room. 1800 K has a deeper, amber-like character. 2000 K is still beautifully warm, with a slightly lighter, more golden feel.

56

mired: the step from 1800 K to 2000 K.

On the mired scale (one million divided by the kelvin value), the same 56-mired step starting from 4000 K would reach roughly 5150 K. Mired is a convenient way to compare colour-temperature steps, but it is not a perceptually uniform scale: equal steps do not necessarily look equally different.7

Bedroom visualised at 2000 K The same bedroom visualised at 1800 K 1800 K 2000 K

Drag the divider, tap the buttons or use the arrow keys. Illustrative visualisation: one AI-generated image shown under two modelled white points. On-screen colour depends on your display and cannot reproduce the spectrum of real light, so the real difference between two luminaires is best judged in person.

Technical note

Tolerance standards such as ANSI C78.377 define nominal correlated colour temperature (CCT) categories through chromaticity coordinates rather than through fixed kelvin steps.5

CCT alone does not fully describe the colour of white light. Two sources with the same CCT can sit above or below the blackbody (Planckian) locus, expressed as Duv, and look slightly greenish or pinkish.6 The visible difference between two real products can only be established by measurement and direct comparison.

The science behind warmer light

Beyond what the eye can see.

Light shapes more than the atmosphere. Its spectrum also matters.

What we see

Model illustration
Hotel suite visualised at 1800 K

Illustrative representation, not a calibrated reproduction of actual LED light. On-screen colour depends on your display.

What the spectrum tells us

Model illustration
  • Selected spectrum
  • Other two references
  • Melanopic sensitivity (peak 490 nm)
  • Melanopic-weighted spectrum, shown ×10

Melanopic DER · model comparison

  • 1800 K
  • 2000 K
  • 2700 K

Illustrative comparison of ideal blackbody spectra at equal photopic illuminance. At the same illuminance, the modelled melanopic EDI is proportional to these values. They do not represent measured MINALOX luminaires; for real LEDs, a lower CCT does not automatically mean a lower value.

Illustrative blackbody reference spectra — not measured MINALOX LED spectra. Ideal radiators calculated from Planck’s law and scaled to the same illuminance. Real phosphor-converted LEDs have different spectra with characteristic peaks, so their melanopic properties must be measured.814

Melanopic sensitivity is highest at shorter visible wavelengths, around 490 nm, but it spans a broad band from violet through blue to green. Blue light is not the only contributor: the result always depends on the whole spectrum.

Research finding

The light we see is not the whole story.

Light does more than help us see. Its spectral composition can also influence biological pathways involved in our daily rhythms. This is why thoughtful evening lighting considers not only colour temperature, but also spectrum, brightness and timing.913

Established fact

The international framework for describing these effects is the CIE S 026 standard. It defines how the light reaching the eye is weighted for the melanopsin-containing cells of the retina (ipRGCs), which play a central role in non-visual responses to light.8

MINALOX philosophy

A smaller number. A different possibility.

Extending the warm end of our DualWhite range to 1800 K gives designers another way to create deeply warm evening scenes. Depending on the actual light spectrum and intensity, such scenes can also support strategies aimed at reducing melanopic light exposure in the evening.

  • AppearanceThe warmer visual appearance is a characteristic of the selected CCT.Established fact
  • Spectrum and exposureThe actual melanopic effect depends on the measured spectrum and on the light that reaches the eye.Established fact
  • Light levelLower evening light levels are an important part of responsible lighting design.9Design recommendation
  • 1800 K or 2000 KA specific biological advantage over 2000 K cannot be established from CCT alone.Established fact

Same CCT. Different spectrum.

Two light sources can share one colour temperature and still differ in their melanopic content.

See the spectral comparison
Technical panel: CCT, SPD, melanopic sensitivity, DER and EDI

These five quantities describe different things and are not interchangeable.

Correlated colour temperature (CCT) · K
The temperature of the Planckian radiator whose colour is closest to that of the light source. It describes colour appearance only; very different spectra can share the same CCT.1
Spectral power distribution (SPD)
How the radiant power of the light is distributed across wavelengths. It is the physical description from which all the following quantities are calculated.
Melanopic spectral sensitivity · smel(λ)
The CIE S 026 action spectrum for melanopsin-based ipRGC responses, with its maximum at 490 nm for the standard 32-year-old observer. It is a weighting function, not a property of the light.814
Melanopic daylight (D65) efficacy ratio (melanopic DER)
The melanopic content of a spectrum per unit illuminance, relative to the D65 daylight reference (D65 = 1). It characterises a spectrum, not a light exposure.8
Melanopic equivalent daylight illuminance (melanopic EDI) · lx
Melanopic EDI expresses the melanopic effect of a light exposure as an equivalent illuminance from a defined daylight reference spectrum. It depends on the spectral irradiance reaching the observer’s eye, so it changes with light level, distance, direction of view and the surrounding light. For a given spectrum, melanopic EDI equals the illuminance at the eye multiplied by the melanopic DER.816
γmel,vD65 = (Emel / Ev) / Kmel,vD65      Kmel,vD65 = 1.3262 mW/lm
Ev,melD65 = Emel / Kmel,vD65 = Ev · γmel,vD65

Model calculation used on this page

Calculated in your browser from the CIE S 026 melanopic action spectrum and the CIE 1931 V(λ) function at 5 nm intervals, 380–780 nm. Ideal model spectra only.1415

Model spectrumMelanopic DER
Blackbody 1800 K–
Blackbody 2000 K–
Blackbody 2700 K–
Continuous spectrum, section 06 (≈ 3000 K)–
Peaky spectrum, section 06 (≈ 3000 K)–

Published recommendation. For healthy adults, Brown et al. (2022) recommend a melanopic EDI of at least 250 lx at eye level during the day, no more than 10 lx in the evening, starting at least three hours before bedtime, and no more than 1 lx in the sleeping environment.9 These are exposure targets measured at the eye, not luminaire properties.

Not covered here. Individual differences, age (CIE S 026 provides an age-related correction), pupil size, earlier light exposure and the time course of exposure. Model spectra and screen images cannot replace measurement.

Two ranges. Two possibilities.

More range doesn’t always mean more relevance.

Scale
MINALOXDualWhite · 1800–4500 K
18004500
Alternative range2000–6000 K
20006000

2700 K

Within MINALOX 1800–4500 K Within 2000–6000 K

Both ranges have legitimate applications. Neither characteristic determines lighting quality on its own: the value depends on the space and how it is used. Swatches are on-screen approximations of each white point.

Experience the atmosphere

Same space. Different feeling.

An open living and dining space with layered architectural lighting
2700 K Within MINALOX DualWhite

Illustrative visualisation: one AI-generated image, re-lit with a colour model of each white point at constant brightness. Real interiors also change with dimming level, spectrum and the mix of light sources.

* 6000 K is shown for comparison and lies outside the MINALOX DualWhite range. The gold mark on the slider shows 1800–4500 K.

Light that follows your day

One space. Many moments.

Kitchen and dining space in soft morning daylight with task light over the island The same space at midday, filled with daylight The same space in the evening with warm, layered light The same space at night with only very low orientation light

Morning

Colour temperature
Brightness
Distribution
Timing

Intelligent lighting is not simply about changing colour temperature. Brightness, timing, distribution and lighting scenes matter just as much.

Example scene values for illustration; every project is planned individually. Morning and daytime images show natural daylight. How light affects people depends on its spectrum, intensity, timing and duration of exposure, not on colour temperature alone.89 All images are AI-generated illustrative visual states.

What makes light beautiful?

Colour temperature is only the beginning.

Two light sources with the same correlated colour temperature (CCT) can still look different. CCT describes the colour of the light itself, not how well that light reveals a room, its materials or the people in it.

Schematic spectral power distributions (SPD) of two light sources. Chromaticity calculated with the tabulated CIE 1931 2° colour-matching functions.15 Illustration only, not measurements of any product.
Practically the same CCT
≈ 3000 K

Colour rendering

How naturally colours and materials appear.

Assessed with metrics such as the Colour Rendering Index (CRI: Ra, R9) or the more detailed ANSI/IES TM-30 method (fidelity Rf, gamut Rg).234 These values are only meaningful when measured on the actual product.

Spectral composition

The wavelengths that make up the light.

Described by the spectral power distribution (SPD). Different spectra can share one CCT yet render surfaces differently, and they can also differ in their non-visual (melanopic) content.18

Colour consistency

How closely different luminaires match.

Chromaticity tolerances are described in MacAdam-ellipse steps (SDCM) or ANSI quadrangles. Duv shows whether white light sits above (greenish) or below (pinkish) the blackbody locus.56

Light distribution

Where light falls and how it shapes the architecture.

Beam angles, glare control, the balance between vertical and horizontal light and the layering of sources often shape the experience of a room more than colour temperature does.

Where light matters

Designed for the way we live.

In homes, hotels and restaurants, the evening is where atmosphere matters most. A range that reaches down to 1800 K adds a deeply warm register, close to the colour of candlelight, while 4500 K keeps clear neutral-white light available for everyday tasks.

Preferred colour temperature also varies with light level, culture, task and time of day, so there is no single rule for every space.10 Settings shown are examples for illustration; every project is specified individually.

The MINALOX philosophy

We don’t design light around the highest number.

We design it around the moments that matter.

Our 1800–4500 K DualWhite standard brings together deeply warm atmospheric lighting and versatile neutral-white illumination.

It reflects our focus on architectural environments, visual comfort, intelligent control and thoughtfully designed lighting experiences.

Our portfolio has evolved towards a consistent standard that supports this approach.

MINALOX

Light beyond numbers.

References & notes
  1. CIE 015:2018. Colorimetry, 4th edition. Vienna: International Commission on Illumination.
  2. CIE 13.3-1995. Method of Measuring and Specifying Colour Rendering Properties of Light Sources. Vienna: CIE.
  3. CIE 224:2017. CIE 2017 Colour Fidelity Index for Accurate Scientific Use. Vienna: CIE.
  4. ANSI/IES TM-30-20. IES Method for Evaluating Light Source Color Rendition. New York: Illuminating Engineering Society.
  5. ANSI C78.377-2017. Electric Lamps: Specifications for the Chromaticity of Solid-State Lighting Products. Rosslyn, VA: NEMA / ANSLG.
  6. Ohno, Y. (2014). Practical use and calculation of CCT and Duv. LEUKOS, 10(1), 47–55. doi:10.1080/15502724.2014.839020
  7. Wyszecki, G., & Stiles, W. S. (1982). Color Science: Concepts and Methods, Quantitative Data and Formulae (2nd ed.). New York: Wiley.
  8. CIE S 026/E:2018. CIE System for Metrology of Optical Radiation for ipRGC-Influenced Responses to Light. Vienna: CIE. doi:10.25039/S026.2018
  9. Brown, T. M., Brainard, G. C., Cajochen, C., et al. (2022). Recommendations for daytime, evening, and nighttime indoor light exposure to best support physiology, sleep, and wakefulness in healthy adults. PLOS Biology, 20(3), e3001571. doi:10.1371/journal.pbio.3001571
  10. Fotios, S. (2017). A revised Kruithof graph based on empirical data. LEUKOS, 13(1), 3–17. doi:10.1080/15502724.2016.1159137
  11. Wyman, C., Sloan, P.-P., & Shirley, P. (2013). Simple analytic approximations to the CIE XYZ color matching functions. Journal of Computer Graphics Techniques, 2(2), 1–11. jcgt.org/published/0002/02/01
  12. McCamy, C. S. (1992). Correlated color temperature as an explicit function of chromaticity coordinates. Color Research & Application, 17(2), 142–144. doi:10.1002/col.5080170211
  13. CIE PS 001:2024. CIE Position Statement on Integrative Lighting: Recommending Proper Light at the Proper Time, 3rd edition. Vienna: CIE. doi:10.25039/PS.b2twa77g
  14. CIE. CIE α-opic action spectra (CIE S 026 dataset, 1 nm). Vienna: CIE. doi:10.25039/cie.ds.vqqhzp5a (accessed 5 November 2026).
  15. CIE. CIE 1931 colour-matching functions, 2 degree observer (dataset, 1 nm). Vienna: CIE. doi:10.25039/CIE.DS.xvudnb9b (accessed 5 November 2026).
  16. CIE. User Guide to the α-opic Toolbox for implementing CIE S 026. Vienna: CIE. doi:10.25039/S026.2018.UG

About the visualisations. All interior images on this page are AI-generated visualisations, not photographs of MINALOX installations. Colour-temperature states are computed: the white point of each kelvin value is derived from Planck’s law and the CIE 1931 colour-matching functions (analytic approximation11), converted to sRGB and applied per channel in linear light, with partial chromatic adaptation and brightness held approximately constant. Chromaticity and melanopic values of the model spectra are calculated from tabulated CIE data;1415 their CCT is estimated with McCamy’s formula.12 Screens cannot reproduce real spectra, so all colours are approximate.

No product measurements. This page does not state measured performance values for any MINALOX product. Product data are given in the respective datasheets.