Quick Answer
The quick answer is yes, mixing white and black pigments or light does make grey. When you mix together white and black paints, the result is a shade of grey. This is because paints absorb and reflect different wavelengths of light. White paint reflects all visible wavelengths, while black paint absorbs all visible wavelengths. Mixing them creates a paint that reflects and absorbs some wavelengths, making it appear grey. Similarly, combining white light and black (absence of light) results in shades of grey. The more white vs black in the mix determines how light or dark the grey will be.
The Science Behind Mixing Black and White
To understand why combining black and white makes grey, we need to dive into some color theory and physics of light.
Pigments and Paint
Paints contain pigments – particles that interact with light by selectively absorbing some wavelengths while reflecting others. Our eyes detect the reflected wavelengths as color.
White paint contains pigments like titanium dioxide that reflect almost all visible wavelengths equally. It appears white because it reflects all colors to our eyes. Black paint is the opposite – its pigments absorb almost all visible wavelengths. When light hits it, very little reflects back to our eyes, so it appears black.
Grey paint contains pigments that absorb some wavelengths while reflecting others. Specifically, grey paint will absorb more of the long and short wavelength colors (red, orange, blue, violet) while reflecting more of the mid-range wavelengths (green, yellow). This partial reflection and absorption of different colors mixes to create the various hues of grey.
So when white and black paint are combined, the result is a paint that reflects some wavelengths (from the white pigments), while absorbing others (from the black pigments). This mix of reflection and absorption appears to our eyes as shades of grey.
Light Waves
We can also understand this concept using light waves. White light contains a balanced mixture of all visible wavelengths of light. It can be created by combining red, orange, yellow, green, blue, and violet light waves together.
| Color | Wavelength (nm) |
|---|---|
| Red | 700 |
| Orange | 620 |
| Yellow | 580 |
| Green | 530 |
| Blue | 470 |
| Violet | 410 |
Black, on the other hand, is the absence of visible light waves. So when white light and black combine, you get a mix of some wavelengths being present (from the white light), while other wavelengths are absent (from the black). Our eyes perceive these partial mixes of light waves as grey.
The more white light vs black in the mix, the lighter or darker the shade of grey will appear. Equal amounts produce a medium grey. More white makes light grey, while more black makes dark grey. When all wavelengths are present, it appears white. When all wavelengths are absent, it appears black. The gradients in between are shades of grey.
Examples of Mixing Black and White
We can see this principle in action in several examples:
Paint Mixing
Artist paints provide a straightforward demonstration. Mixing together white and black oil or acrylic paints on a palette creates a grey paint. The more white vs black used in the mix determines how light or dark the grey turns out.
Colored Pencils
Blending black and white colored pencil pigments on paper produces grey. Layering more black over white makes the greys darker, while layering more white over black makes them lighter.
Printers
Inkjet, laser and other printers can create shades of grey by combining black ink with white space on the page. More black ink vs white space controls the lightness/darkness of the grey. Black text on a white page appears dark grey from a distance, for example.
LED Lighting
LED light bulbs can make grey by combining white light emitting diodes (LEDs) that emit all colors, with absence of light. Adjusting the brightness of the white LEDs vs unlit LEDs allows creating different greys.
Computer Displays
On LCD or OLED screens, pixels can display greys by outputting a mix of full white light and black (turned off). Settings with more white vs black pixels produce lighter and darker shades of grey.
Black and White Photography
Black and white film or digital camera images showcase many tones of grey. Light reflected off subjects exposes the film or sensor. More light exposure produces lighter greys, while less exposure gives darker greys.
The Psychology of Black, White and Grey
The mixing of black and white to create grey also has psychological symbolism:
Black and White
Black and white are seen as opposites, extremes. They represent polar opposites, good vs evil, day vs night. Culturally, black is associated with bad, death, and evil; while white represents good, purity, and innocence.
Grey
Grey is the mixture, the in-between. It represents balance, neutrality, compromise. It sits between the extremes of black and white, incorporating elements of both. Grey is more subdued, nuanced, and realistic compared to stark black and white thinking.
This reflects how grey contains both light and dark, in shades of balance between the two extremes. Mixing black and white paint or light comes to represent mixing their symbolic meanings. Grey contains both halves in a blended, moderate way compared to the opposites of black and white alone.
Conclusion
In summary, combining black and white pigment or light does produce various tones of grey. This is due to the blending of wavelengths absorbed and reflected by the pigments, or present and absent in the light waves. Shades of grey contain both properties of black and white mixed together into new hues. Beyond color theory, this also represents philosophically blending the extremes of black and white into balanced, nuanced greys.
