Why did Grand Seiko choose purple? Introducing the color philosophy and styling tips from the SLGB005

Purple has recently become a popular color for watch dials. Unlike blue or green, this color may not be familiar to many people. This time, we will focus on purple and explore the natural phenomena surrounding this color, as well as the effects it has, together with Grand Seiko. We will also teach you color combinations that go well with the limited edition SLGB005 model with a purple dial.

There are many different shades of purple. SLGB005 Overall Color Explanation

　The Cal. 9RB2, an ultra-high precision movement with an annual accuracy of ±20 seconds, was announced in April 2025. The SLGB005, announced in September, joins the UFA (Ultra Fine Accuracy) models equipped with the same movement.

　The dial color of this watch is deep purple, but the impression changes surprisingly depending on the amount of light. When there is not much light, it appears a deep purple that is almost black, as shown in the photo below, and the embossed pattern is subdued.

　However, when light hits the dial, an intricately embossed pattern emerges, along with a purple gradation that gradually darkens from the center to the periphery.

　The bracelet is made of Everbrilliant Steel, which has a slightly whiter, harder shine than regular stainless steel, and coolly complements the mysterious purple color of the dial.

　In addition, the embossing and gradation are more pronounced in sunlight.

Dyed purple? The wonders of the frost-covered forest

　According to Seiko, the dial of this model expresses "the mystical scene of dawn as the frost-covered forest quietly awakens." So, when does the frost-covered forest turn purple? It's the result of a truly mystical time phenomenon that occurs during the time period known as twilight, where Rayleigh scattering and red light arriving from the horizon mix together.

The beautiful time called twilight

　Twilight is when the sun is below the horizon (or horizontal line), but the sky is not completely dark and there is a slight sense of light.

　For a brief moment, you can see a purple light in the sky. At this time, sunlight travels a long distance through the thick atmosphere, so only red light with a long wavelength reaches the sky. This light mixes with the blue light that is seen due to Rayleigh scattering in the sky, creating the purple color. It is this light that dyes the pure white frost-covered trees purple.

　Pure purple light also exists in sunlight, but it is harder for humans to perceive compared to other colors due to the characteristics of their vision, and it is harder to see on its own because it scatters more strongly than blue. Therefore, purple light is perceived during times when red light and blue light are mixed together.

The Rayleigh scattering phenomenon is surprisingly close to us!

　Rayleigh scattering may sound complicated, but it is a familiar phenomenon that most people see every day. Simply put, it is a phenomenon in which light with short wavelengths (blue light) in the range of light that humans can see (visible light) hits molecules in the air and is scattered, which is why the sky appears blue.

　When this light phenomenon coincides with the red light from the horizon, the frost-covered forest turns purple, provided certain conditions are met, such as clear skies and clean air.

What color is "purple"?

What image comes to mind when you hear the word "purple"? Long ago, during the time of Prince Shotoku, purple was considered a noble color, as it was designated the highest rank in the twelve-ranked social hierarchy in Japan. Even today, purple, especially dark tones, is a color that easily conveys a sense of luxury.

　In terms of color therapy, purple is said to be effective for spiritual integration (balancing opposing emotions) because it is a color created by mixing two colors with completely opposite properties, red and blue. It is also said to be the color of healing, regeneration, and overcoming.

　Many people like purple, but find it a bit difficult to wear. So, we'll be introducing some easy-to-wear color combinations, focusing on the dial color of the SLGB005.

Recommended color combinations for SLGB005 for casual holidays

　When wearing a watch with a colored dial, you might be tempted to coordinate it with monochrome (white, gray, black) or monochrome with denim. Of course, these coordinations are lovely, but for those who want to enjoy fashion with a little more color, I would recommend a color scheme like this.

①Khaki x Light Beige x Dark Purple

　If you plot this combination on a color wheel (a diagram in which colors are arranged in a continuous circle like a rainbow), you get khaki = (dull) green, light beige = (lightened) orange, and dark purple = violet. These colors are based on a triad color scheme, which connects the color wheel with a triangle. By using this color scheme, even though it uses a lot of color, it creates a sophisticated atmosphere.

②Beige x Brown x Dark Purple

　If we plot this combination on a color wheel, it would look like beige and brown = (a dull shade of) orange, and dark purple = purple. This color is based on a contrasting hue scheme (a difference of 8 to 10 colors on the color wheel). By lowering the saturation (vividness) and value (brightness) of the orange, the overall impression becomes more subdued.

③ Shades of blue and dark purple

　If you plot this combination on a color wheel, it would be light blue and dark blue = blue, and dark purple = purple. This color scheme is based on analogous hues (2-3 colors apart on the color wheel). By using similar colors, it creates a sense of unity.

　Using these rules will make coordinating watches easier, but there's no need to be too faithful to the color scheme. In fact, the colors used in this image are slightly different from the so-called textbook color scheme, but the coordination is still successful. However, it's good to have the knowledge. Also, this time I've deliberately avoided the standard style of watch coordination, which is to "pick up the color of the dial." I hope this is helpful.

Have fun with purple

　The SLGB005's dial expresses the mystical moment when the frost-covered forest turns purple. The way it looks changes dramatically depending on the lighting and the intensity of the sunlight, so it will show off a new look in a variety of situations. While enjoying these changes, you might also enjoy color coordination with the watch as the main focus.

Author profile

Mutsuyo Ito
He provides a wide range of consulting services related to "products, places, and people" at sales sites, including color supervision and image consulting for watch manufacturers, personal color diagnosis at event venues, and customer service training. He holds numerous qualifications, including a Grade 2 watch repair technician, a J-color certified instructor, and a GIA AJP. He is the representative director of parakeITO Co., Ltd. Website:https://www.mutsuyo-ito-parakeito.com/