White light contains all the colors of the visible spectrum. Technically, any color can be produced as a neon light, including white, by combining different neon gas types and phosphor coatings in the tube. However, pure white neon is difficult to achieve and not commonly used in neon signs. Most white neon applications mix other colors to create an off-white or tinted white effect. So while white neon is possible, it’s rarely implemented in practice.
How Neon Lights Work
Neon lights work by running electricity through tubes filled with neon or other noble gases at low pressure. This excites the gas atoms, causing them to emit light at specific wavelengths. Different gas types produce different colored light:
To create other colors, the inside of the glass tube is coated with different phosphors – chemicals that fluoresce and produce colors when excited by the ultraviolet light emitted by the ionized gases. Combining different gases and phosphor coatings allows neon tubes to produce a wide range of colors.
Challenges of White Neon
While white neon is possible in theory, it is difficult to achieve in practice:
– Krypton produces a bluish white light due to unbalanced spectral emission. This is not a pure white.
– Mixing phosphors to create white requires balancing the emission from multiple phosphors, which is technically challenging. Small variations in temperature or voltage can throw off the color balance.
– White phosphor mixtures tend to degrade over time at different rates, shifting the color over time. Replacement parts may not match exactly.
– Impurities or outgassing can discolor the tube over time. White is especially sensitive.
– White neon has low visual impact compared to brightly colored neon. Does not stand out well.
For these reasons, white neon is rarely used:
Typical White Neon Applications
Instead of pure white, neon sign makers typically use mixes of neon and phosphors to create off-white or tinted white effects. Some examples include:
– Mixing neon gas colors like red and blue to create a pinkish-purple white.
– Using gold or amber phosphors to create a warm white tone.
– Adding blue phosphor to counter the pink tones from neon, making a neutral white.
– Using diffusion or frosted glass to soften and blend colors into white.
– Combining neon with LEDs to add pure white elements.
These approaches avoid the technical challenges of pure white while creating pleasing off-white neon colors. The result is often a creamy, warm, or soft white rather than a harsh blue-tinged white.
Achieving Pure White Neon
To create the purest white neon possible requires:
– Krypton or argon-xenon gas mixture tuned for spectral balance
– Custom phosphor blend formulated for whiteness and stability
– Color monitoring and adjustments during manufacture
– Protection from UV, oxygen, and contamination
– Careful voltage regulation and temperature control
– Isolation from external light sources
– Monitoring and maintenance to detect color shifts
With attention to these factors, neon artists can produce neon that approaches a pure white studio reference light. But variation and degradation remain a constant battle.
Better Alternatives for White Lighting
For most lighting applications requiring white, LEDs are now a better choice compared to neon:
– LEDs can produce a pure white at any color temperature.
– White LEDs have excellent color stability over time.
– LED white lighting has high brightness and visual impact.
– LEDs are energy efficient and have very long lifespans.
– LED strips can flexibly produce any color.
– Digital LEDs can dynamically change color and patterns.
With these advantages, LED lighting has become the dominant choice for white lighting in signs, displays, and commercial lighting applications. Neon is still unsurpassed for producing bright, saturated, jewel-like colors, but white LEDs outperform it for white and dynamic color effects.
In summary, while white neon is possible, it presents numerous technical challenges and limitations. Off-white neon effects are more commonly used in signs and art. For pure and efficient white lighting, LEDs are now the superior choice compared to neon tubes. Neon still excels at producing vibrant and saturated colors, but not white. So while white neon exists, it is rarely the optimal choice.