There’s a common misconception that mixing red and blue paints or pigments will produce black. While combining complementary colors on the color wheel, like red and blue, will create a dark brown or grey shade, the resulting color will not be a true black. The notion that red + blue = black is based on an oversimplification of color theory and pigmentation.
What Colors Make Black?
In basic color theory, when you mix all the colors of light together, the result is white. Conversely, the absence of all colors of light leads to black. This works with additive light mixtures like television or computer screens, where the primary colors of light are red, green, and blue (RGB).
However, that’s not how pigment mixing works. With paints, dyes, and inks that use subtractive color mixing, the primary colors are cyan, magenta, and yellow. When you combine all the primary colors of pigment together, the result is black or nearly black because all wavelengths of light are being absorbed.
So technically speaking, if you want to mix colors to create true black paint, you would mix equal parts cyan, magenta, and yellow pigments. Adding complements like red and blue will only darken the mixture towards grey or brown.
Why Red and Blue Don’t Make True Black
There are a couple reasons why mixing red and blue paint doesn’t make an ideal black:
- Red and blue are not true primary colors in the subtractive color model
- Combining complements neutralizes color intensity
Let’s look at these factors more closely:
Red and Blue Are Not Primaries
As mentioned above, the primary colors in pigment are cyan, magenta, and yellow because they each represent one of the three subtractive primary colors in light. Red, blue, and yellow are considered the secondary colors.
So while red and blue are complementary hues, meaning they’re directly opposite each other on the color wheel, they’re not the key building blocks for creating black through pigment mixing.
Complements Neutralize Each Other
When complementary colors like red and blue are combined, they have a tendency to mute or neutralize each other’s color intensity. This makes sense if you think about color theory – complements contain the exact wavelengths of light that the other color absorbs.
When they mix together, the vibrant qualities of the individual colors get canceled out. While this neutralization creates darker shades, it usually doesn’t result in a truly deep, opaque black.
How to Mix Black Paint
Here are a couple ways you can actually mix black paint or pigment:
Cyan + Magenta + Yellow
As explained above, mixing equal parts of the three primary colors of pigment – cyan, magenta, and yellow – will create true black. This covers all parts of the visible light spectrum to absorb all colors of light.
Burnt Umber + Prussian Blue
You can mix a rich black using burnt umber, which is a dark brown pigment, and Prussian blue, a dark violet-blue. These earthy hues contain rich, dark tonal values that layer well.
Mars Black Pigment
For convenience, you can simply use a premade Mars black pigment rather than mixing your own. Mars black is made from iron oxide and is extremely opaque for covering over other colors.
Tips for Mixing Black Paint
Here are some helpful tips when mixing your own black paint:
- Use soft body acrylics – They have more pigment and mix together smoothly.
- Mix in a palette – Glass, porcelain, or coated paper palettes work best.
- Add white to lighten – White tempers black and allows you to make shades of grey.
- Deepen with umber or Prussian blue – For an intense, opaque black.
- Check opacity on white surface – Fully opaque black will completely cover white.
How Dark Colors Mix
Generally speaking, the more pigment a color contains, the darker the resulting mixtures will be. Here’s a look at how some common paint colors mix together:
| Color 1 | Color 2 | Mixture |
|---|---|---|
| Cadmium Red | Cerulean Blue | Dark purple |
| Burnt Sienna | Ultramarine Blue | Dark mud brown |
| Dioxazine Purple | Prussian Blue | Dark blackish purple |
As you can see, mixing any colors with high amounts of pigment will produce rich, dark hues. Adding white to these mixtures will lighten them towards a grey.
Does Black Absorb Heat?
Since black absorbs all visible wavelengths of light, it can absorb a lot of heat energy. This is due to the way dark colors interact with light compared to lighter ones.
When light hits a surface, it either gets absorbed, transmitted, or reflected. A perfectly black surface would absorb almost all of the light rather than reflecting it. This light energy gets converted to heat.
Lighter colors like white reflect most of the light, repelling heat. That’s why you feel hotter wearing a black shirt in the sun versus a white one.
What Colors Reflect Heat Best?
The best colors for reflecting heat are light, bright, or pastel versions of colors. Here is a general ranking of some colors based on heat reflection:
- White – reflects the most heat
- Beige, light yellow
- Light green, light blue
- Red, orange
- Dark blue, purple
- Dark green, brown
- Black – absorbs the most heat
Lighter shades reflect the most wavelengths of light while darker shades absorb more. Pastel colors with added white also bounce back light energy.
Does Black Attract Heat?
Black doesn’t necessarily attract radiant heat, but it does absorb heat exceptionally well compared to lighter colors. This ability to convert light into thermal energy can make black feel hot.
For example, a black car left in the sun will get hotter inside than the same car in white. The black exterior rapidly absorbs the sun’s rays and converts it to heat.
This principle extends to other uses too. Black clothing absorbs body heat in colder weather, while white reflects it back. So black draws in radiant heat from light rather than attracting thermal heat.
Does Black Paint Protect From Heat?
Using black paint on a surface won’t really provide much protection from heat. While it’s true that black absorbs solar energy rather than reflecting it, the color alone doesn’t provide meaningful insulation.
However, combining black paint with other materials can potentially reduce heat transfer:
- Black acrylic paint on metal – Provides minimal insulation
- Black paint on wood – Lowers heat conduction slightly
- Flat black paint – Better heat resistance than gloss
- Black paint + insulation – Most effective for blocking heat
The main way that black paint could help is by absorbing UV radiation before it penetrates the material underneath. But the paint itself won’t slow heat conduction much.
Conclusion
In summary, mixing red and blue pigments won’t make a true black color. While combining complements can create dark shades, real black requires all visible wavelengths of light to be absorbed. The closest mixture involves cyan, magenta, and yellow primary pigments.
Black is the darkest color because it absorbs the most light energy, converting it to heat. Lighter colors like white reflect light instead, repelling heat. So black draws in and traps radiant light, rather than attracting thermal heat.
Using black paint alone doesn’t provide substantial insulation from heat. But it can absorb UV rays on surfaces when combined with other insulating materials. The notion that red + blue = black is really just an oversimplification of how subtractive color mixing works with pigments.
