The x7 Color System™ is a science... and an art

When LEDs first appeared on the market, they got a lot of attention. People were amazed that the technology they had grown accustomed to seeing as indicators on computers or under backlit keys was able to produce enough light to illuminate an object, and without using as much energy as other lighting fixtures. For lighting designers, that amazement quickly turned to disappointment when they saw how limited that LED light was. When lit by a typical LED fixture, people and objects look strangely washed out or gray. And when put up against a tungsten fixture, the LED light stands out and looks electronic, fake and flat.

Then the x7 Color System – which combines a carefully proportioned array of LED colors onto a single
LED luminaire – was introduced, and LED lighting found its place on traditional lighting rigs... and in designers’ hearts.

But why does the x7 System produce better light than traditional LED lights?

The x7 Color System was designed around an expanded understanding of additive color-mixing: more color in means better light out. ETC LED fixtures combine many different emitters – from five to seven different colors – on one unit. Most conventional LED fixtures use only three colors – red, green and blue (RGB) – and the only deep colors they can produce are those three colors. Hues like golden yellow, deep turquoise, and intense purple are impossible to create with RGB. Instead, RGB produces only rough approximations of these hues. Depending on the lighting application, these approximate colors can be very unsatisfactory.

This concept can be explained by looking at a color wheel – like the one to the left – where the most vibrant colors are on the edges and the lightest, least-saturated colors are in the middle. An RGB fixture’s output can be plotted with three points: one each in the parts of the circle representing red, green and blue. Connecting those points shows the range of colors that can be created with RGB color mixing. Take amber, for example. The amber hues within the RGB triangle are not very saturated, and the deepest amber color on the color wheel lies far outside the limits of the RGB range.

Some LED fixtures add amber or white LEDs to their arrays to try to achieve better color output, but typical RGBA fixtures include too few amber LEDs. The small quantity of amber emitters doesn’t properly balance color, leaving too much of the spectral weight with the fixture’s red and green emitters. RGBW and RGBAW fixtures do not solve this problem with the inclusion of white LEDs. While the added white emitters can enhance white-light output and somewhat improve the illumination of skin tones, white does not change the color range of the fixture.

With the x7 System, more colors are added to the LED mix, and they are balanced correctly to increase the range of saturated colors that fixtures can produce. Taking the same color wheel and plotting seven colors – red, orange, amber, green, cyan, blue, and indigo – one can see that most of the gaps left by RGB fixtures are filled. The saturated amber color that RGB misses is possible with x7, as is a range of purples, turquoises, magentas, and many other vivid colors.

This process of expanded additive color mixing is similar to what lighting designers already do on a regular basis when they use multiple fixtures in a lighting plot. LED fixtures with the x7 Color System are able to mimic the performance of tungsten lights with gels and filters, not only in their apparent color but also in their actual spectral composition. This means that ETC LED fixtures are uniquely able to blend seamlessly into a lighting rig alongside conventional luminaires.

Because of their expanded spectrum, x7 System fixtures can also accurately illuminate the coloring of costumes, set pieces, skin, and makeup. Hues in illuminated objects are rendered in a balanced way that correctly correlates with both tungsten and natural daylight illumination. RGB lighting, on the other hand, tends to exaggerate colors and make illuminated objects appear unnaturally bold, even lurid, and objects with similar but different colors lose their distinction under RGB lighting. The precisely balanced white light of the x7 Color System softly adjusts to illuminate skin tones without the unnatural ruddiness and gray coloring that RGB fixtures produce.

Each ETC LED fixture uses aspects of the x7 System, and the ETC family includes a variety of color mixes for different applications. Lighting professionals no longer need to compromise when it comes to using LED fixtures. The x7 Color System is a sophisticated answer to their desire for effective LED lighting.