XELIOS-iO: Portable LED Lighting for Color Evaluation

Why Lighting Matters in Color Evaluation

Color appearance changes under different light sources because each source has its own spectral distribution. Ordinary indoor lighting can also change as lamps age, making it difficult to use the same color reference consistently at a desk, in a conference room, or at a customer site.

Natural sunlight has a continuous spectrum across the visible range and is an ideal reference for evaluating colors. But sunlight is not always available indoors, in spaces without sufficient daylight, on cloudy or rainy days, or at night.

XELIOS-iO accurately reproduces sunlight to provide a dependable light environment for color evaluation wherever it is needed. With personal sunlight available at a desk, users can examine samples without moving them to a window or outdoors. Its portability also helps teams create comparable viewing conditions across different workplaces.

XELIOS-iO Configurations at a Glance

• Standard / Tabletop Configuration — Personal Sunlight

  In Italian, “io” means “my”.

  XELIOS-iO provides “personal sunlight”—a desktop stand-type light that reproduces sunlight directly at your workstation. This helps teams evaluate product colors and materials without depending on the time of day or the light available through a window. A flexible-tube stand supports tabletop positioning; the stand is sold separately where indicated in the product illustration.
• Portable and Hand-Held Configuration

  The compact XELIOS-iO light can be carried in a bag and brought to meetings, customer offices, or locations with inadequate ambient lighting. Weighing approximately 0.6 kg, the portable light fits easily in a bag.

  The rechargeable, cordless hand-held type brings light to areas that are difficult to illuminate with a fixed system, including the inside and outside surfaces of products. The hand-held type provides approximately two hours of illumination after approximately two hours of charging.

Developed for Portability

Customers asked for an artificial solar light that could be used at meetings and presentations instead of only in large fixed installations. After two years of development, SERIC created a smaller, lighter, lower-cost portable iO design compared with its earlier XC-type lighting system.

Accessories and Diffuser-Type Options

The product illustrations show a flexible stand, mounting clip, hand-held unit, and aluminum carrying case. The diffuser-type illustration compares the illumination patterns of standard and diffuser configurations.

Where XELIOS-iO Can Support Color Checks

Portable daylight-like lighting helps professionals assess the appearance of products and samples at the places where decisions are made. XELIOS-iO supports color reviews in product design and material selection, apparel manufacturing, photography and visual presentation, cosmetics and nail colors, and customer meetings.

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  Product Design and Material Samples

  Compare the appearance of product finishes, materials, and sample colors during design reviews.
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  Apparel and Textile Color Checks

  Review fabric samples and color differences during development, merchandising, or product discussions.
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  Photography and Visual Presentation

  Inspect the appearance of colors when preparing product photographs or visual presentations.
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  Beauty and Nail Color Comparison

  Examine cosmetic or nail color samples using a dedicated light source as part of a visual comparison.
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  Customer Meetings and On-Site Reviews

  Bring a portable lighting option to a conference room or customer site when ambient lighting makes sample comparison difficult.

Color Evaluation at Workstations and Customer Sites

Bring XELIOS-iO into a meeting room, presentation, or customer office to examine colors under a consistent reference light. The cordless hand-held configuration makes it easier to inspect details and internal surfaces that fixed lighting cannot reach.

Teams in different offices or countries can use XELIOS-iO when discussing the appearance of samples. When iO lighting is available at both locations, colleagues can compare colors over the telephone or during a video conference rather than relying only on travel to the site.

By bringing a consistent light source to the places where color decisions are made, XELIOS-iO helps improve the accuracy of product development and sales discussions and strengthens customer confidence. Its portability can reduce development time, travel expenses, and the cost of rework caused by color differences.

Customer Comments

• “Colors appear beautifully, and slight differences in color can be seen clearly.”
• “I appreciate being able to check product and sample colors under stable amounts of light.”
• “The spectral distribution is close to that of sunlight.”
• “I chose it because it is a good approximation of sunlight.”
• “I feel that there is almost no difference from sunlight that shines into the room.”
• “The price was what decided it for me.”

Why Spectral Distribution Matters

Natural sunlight contains a broad, continuous spectrum. Light sources with gaps or sharp peaks in their spectral output can change the perceived appearance of colors, even when the samples themselves are unchanged. Some fluorescent and metal-halide sources have strong emission lines or gaps, while halogen and incandescent sources differ from sunlight at shorter wavelengths.

SERIC developed artificial solar lighting to reproduce the spectral characteristics of sunlight. XELIOS-iO uses this expertise to deliver a high-quality reference light for color evaluation.

SERIC's Three Requirements for Accurate Color Evaluation

• SERIC established the following requirements for light sources used in color evaluation and presented the work at color-related academic conferences, including the Color Optics Conference, the Japan Academy of Color for Dentistry Academic Conference, and the International Color Association AIC Color97.

  1. High color rendering: An average color-rendering index of at least 96, ideally as close to 100 as possible.
  2. Daylight-like color temperature: A color temperature close to sunlight, approximately 5000–6000K.
  3. Sufficient illuminance: Enough light intensity for the intended color-evaluation task.
• SERIC also specifies three cautions for color-evaluation light sources:

  1. Long-term stability: The performance characteristics underlying the three requirements should not deteriorate through aging.
  2. Spectral continuity: Light should have a continuous spectrum without excessive emission-line peaks.
  3. Balanced performance: All three requirements must be considered together; none should be overlooked.

XELIOS-iO is designed to meet these requirements and provide stable artificial sunlight for precise visual color evaluations.

Chromatic Aberration and Lens-Free Lighting

Chromatic aberration occurs when a lens refracts different wavelengths by different amounts, producing color fringing and changes in the perceived colors of an illuminated object. SERIC's XELIOS-iO design does not use a lens and eliminates chromatic aberration, enabling objects to be viewed in their natural colors.

The comparison illustration shows the different light spots produced by an ordinary lens-based LED light source and XELIOS-iO.

Color Temperatures and Specifications

XELIOS-iO is available in two color-temperature types: 5500K and 6500K.

The 5500K type is designed to reproduce sunlight within the approximately 5000–6000K color-temperature range. The 6500K type includes the LE-9ND65 model, which conforms to the D65 standard illuminant specified in JIS Z 8720.

Color Rendering and Model Specifications

XELIOS-iO offers excellent color-rendering performance, with an average color rendering index (Ra) of approximately 97. LE-type models weigh approximately 450 g, while LH-type models weigh approximately 650 g. Specifications vary by model and region. See the regional model information below for details.

For detailed model codes, power requirements, and available options, see the Asia & U.S. or Europe specifications in the regional model section below.

High Color-Rendering Performance

XELIOS-iO achieves an average color-rendering index (Ra) of 97 or higher, delivering exceptionally high color-rendering performance in a portable artificial solar light. The high rendering performance helps users evaluate the appearance of materials, products, and skin tones with clarity.

Power and Practical Specifications

XELIOS-iO supports AC 100–240V power sources, making it suitable for work in offices and on overseas business trips. An adapter plug is not included and should be supplied separately as required for the destination.

The rechargeable hand-held configuration provides approximately two hours of light after approximately two hours of charging. XELIOS-iO also includes LE-type and LH-type configurations, and light output may vary slightly between individual units.

The comparison figures illustrate XELIOS-iO alongside other SERIC lighting systems, covering differences in size, weight, price, lamp life, illuminance, and optical characteristics.

Spectral Distribution and Color Rendering

Spectral Distribution Close to Natural Sunlight

SERIC's artificial solar lighting technology reproduces a spectrum extremely close to natural sunlight. XELIOS-iO's 5500K type is developed to match the color temperature of daylight in the 5000–6000K range. Natural sunlight reaching the ground within approximately two hours before or after noon on a clear day provides an important reference for true color appearance.

The spectral charts compare the 5500K type with sunlight and the 6500K type with a D65 reference.

Ra and R1–R15 Color Rendering

The general color-rendering index Ra is the average of the color-rendering indices R1 through R8. The indices R9 through R15 describe additional special colors. R15 is especially relevant to the reproduction of Japanese skin tones.

With its Ra of 97 or higher, XELIOS-iO supports accurate color evaluation not only of materials and objects but also of human skin. XELIOS-iO also achieves an R15 value of 97 for skin-tone rendering.

The R1–R15 color-rendering chart shows the individual test-color indices used in color appearance evaluation.

Comparing Different Light Sources

Colors can appear different under XELIOS, fluorescent lighting, and incandescent lighting because their spectral distributions differ. Fluorescent and metal-halide lamps have characteristic dips or emission lines, while incandescent and halogen lighting provide relatively less energy at shorter wavelengths. Artificial solar lighting is designed to bring the spectral distribution closer to that of natural sunlight, supporting fine color comparisons that are difficult under conventional lighting.

The comparison photographs and spectral graphs illustrate how color appearance and wavelength distribution differ between light sources.

XELIOS-iO Model Information by Region

Discuss Your Color Evaluation Requirements

• What materials, colors, or product surfaces will you compare?
• Where will the light be used—in a fixed work area, at a customer site, or in another setting?
• Would a tabletop arrangement or a hand-held configuration be more useful?
• Do you need to discuss a nominal 5500K or 6500K color-temperature option?
• In which country or region will the product be used?

Frequently Asked Questions

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  What is XELIOS-iO used for?

  XELIOS-iO is portable LED artificial solar lighting for evaluating the appearance of colors in product design, textile and material selection, photography, cosmetics, customer meetings, and on-site inspections.
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  What color-temperature options are available for XELIOS-iO?

  The series includes 5500K and 6500K versions. Choose the configuration that suits your color-evaluation work and region.
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  What is the difference between tabletop and hand-held XELIOS-iO?

  The tabletop configuration provides personal sunlight at a workstation. The rechargeable, cordless hand-held type brings the light close to samples and areas that are difficult to reach with fixed lighting.
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  Where can I find XELIOS-iO specifications for my region?

  Use the Asia & U.S. or Europe model-information links on this page to view model codes, power requirements, and product configurations.
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  Do all XELIOS-iO configurations have the same specifications?

  No. Model codes, weight, power configuration, accessories, and other specifications differ between the available configurations. Refer to the model information for the version you plan to use.

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