Bees have fascinating color vision that allows them to see colors that humans can’t. Their perception of color guides many aspects of their behavior, including what flowers they visit to collect pollen and nectar. Understanding what colors bees are most attracted to can help gardeners and farmers design plantings to attract pollinators.
How do bees see color?
Bees have compound eyes with thousands of individual lenses. Each lens focuses light onto sensory cells that detect color and motion. The sensory information from all the lenses is integrated by the bee’s brain to create images.
Compared to humans, bees see a wider range of colors in the ultraviolet spectrum. They also see more shades of blue, green, and yellow. Bees can’t see the color red very well. Their visual spectrum ranges from dark blues and purples through to dark oranges.
Bees have three types of color receptor cells in their eyes that allow them to see this wide spectrum:
- UV receptor cells detect ultraviolet light
- Blue receptor cells detect blue light
- Green receptor cells detect green, yellow, and orange light
The combination of signals from these three types of cells gives bees their unique color vision. The bee brain processes the mixture of signals to discriminate between colors.
What flower colors attract bees?
Many flowering plants have evolved colorful petals that specifically appeal to pollinators like bees. Bees are attracted to flowers that are purple, violet, blue, green, yellow, white, and orange.
Bees particularly favor flowers in the blue-to-ultraviolet range. The most attractive flower colors include:
- Purple
- Violet
- Blue
- Yellow
- White
- Ultraviolet patterns invisible to humans
Flowers that look blue or purple to us often have ultraviolet patterning that guides the bees to nectar rewards. Some flowers even have ultraviolet-reflecting “bullseye” patterns leading to their center.
Bees are drawn to these flower colors because of their need to find nectar and pollen. Visiting blue, purple, and yellow flowers maximizes their foraging success.
How bees perceive color
To understand why bees prefer certain flower colors, it helps to understand how bees perceive color differently than humans.
The three types of photoreceptors in bee eyes detect overlapping ranges of the color spectrum. Research shows that bees probably see colors by comparing levels of stimulation of their ultraviolet, blue, and green receptors.
Rather than seeing colors as a rainbow continuum, bees may perceive them in combination bands. So they don’t see “green” or “red” the way humans do.
Experiments that trained bees to associate sugar rewards with colored cards showed these color bands include:
- Ultraviolet
- Violet + purple
- Blue
- Blue-green
- Green
- Yellow
Flowers that have high ultraviolet reflectance, or that reflect strongly in the violet-to-blue range, are very visible and attractive to bees.
Bee vision experiments
Scientists have experimented with artificial flowers to study bee color preferences and vision.
In a lab setting, bumblebees were offered a series of artificial flowers with sugar water rewards. The different flowers had color patterns ranging from violet to yellow. Researchers tracked which “flower” colors the bees visited most frequently.
The results showed the bees had an innate preference for violet, purple, and blue flowers. The bees visited yellow and green flowers significantly less often.
Similar studies found bees are able to learn to associate new colors with nectar rewards. But they still prefer their instinctive favorites in the ultraviolet-to-blue spectrum.
Flower color evolution
Flowers across many plant species have evolved to match the vision and color preferences of pollinating insects like bees.
Many flowers have ultraviolet pattern guides on their petals that are invisible to humans. These guide bees straight to the flower’s nectar and pollen.
Flowers pollinated specifically by bees tend to be blue, purple, or yellow. Bees rely on these flower colors to find food effectively.
In contrast, flowers pollinated by birds and butterflies tend to be red. These insects see the color red better than bees can.
Natural selection led the flowers favored by each pollinator to adapt colors that ensure effective visits.
How bees use flower color cues
Bees associate color with nutritional rewards. When foraging, bees learn to recognize which flower colors will provide them with carbohydrate-rich nectar and protein-packed pollen.
They develop flower color preferences based on experience with nectar rewards. Then bees seek out familiar, profitable flower colors.
Some examples of how bees use color cues include:
- Bees innately prefer violet, purple, blue, and yellow flowers which are high in nectar guides.
- They associate patterns, like ultraviolet bullseyes, with nectar.
- Bees learn which specific colors indicate nutritious flowers.
- If rewarded with sucrose syrup, bees will learn to visit any color, including red.
- Bees remember flower colors to return to those food sources.
Together with floral scent, flower color helps bees zero in on the best flowers. Bees learn and exploit subtle variations in color to determine which plants offer them the highest nutritional payoff.
How humans can use flower colors to attract bees
Gardeners and farmers can take advantage of bees’ color vision to design floral plantings that bring in pollinators.
Choosing a variety of flowers in bee-attractive colors creates an environment full of visual cues that draw the bees in.
Some tips for using flower colors to attract bees:
- Plant groupings of violet, purple, blue, yellow, and white flowers.
- Include flowers with ultraviolet nectar guides like sunflowers.
- Use flower varieties bred specifically for pollinators.
- Go for native plants since bees have innate recognition of those colors.
- Combine early and late blooming flowers to provide color all season.
- Allow herbs like thyme, basil, and lavender to flower for color and scent appeal.
- Avoid large amounts of red flowers, which bees don’t perceive well.
- Provide color variety and use mass floral displays.
Choosing a wide palette of bee-friendly colors will create an attractive and healthy habitat for pollinators in any yard or garden.
Risks of colors that deter bees
While bees favor blue, yellow, and ultraviolet flowers, some colors seem to repel or disorient them.
Red flowers are generally avoided since bees can’t see the color red well. There is also evidence that bees avoid very dark colors.
In lab experiments, bees seem to ignore black or gray targets. Flowers in dark shades of brown, maroon, crimson, and black are likely hard for them to distinguish.
Research shows that honeybees struggle to differentiate between similar shades of green. Different greens look like the same color to bees. This can make it challenging for bees to interpret floral signals.
Extremely pale flowers, especially white ones, also provide little color contrast. Flower patterns and nectar guides normally help bees orient on pale blossoms. Solid white or pale yellow flowers may be difficult targets.
In nature, bees tend to favor more vivid blues, purples, and yellows. Gardeners can support bees by choosing intense flower colors over very pale or dark shades.
Conclusion
Bees have specialized visual systems that allow them to see ultraviolet light and distinguish between blue, green, and yellow wavelengths. This gives them a unique perspective on floral colors.
Selective pressures led the flowers that bees pollinate to evolve colors and patterns that appeal specifically to bee vision. Bees are innately drawn to purple, violet, blue, and yellow blossoms.
Gardeners can help attract pollinators by choosing a diverse palette of bright blooms in bee-friendly colors. Avoiding very dark, pale, or red flowers creates an environment full of floral cues that call the bees in.
Understanding what bee-attractive colors are makes it possible to design healthy habitats where bees will thrive and carry out their essential pollination activities.
Frequently Asked Questions
What are bees most attracted to?
Bees are most attracted to flowers in the violet, purple, blue, and yellow color range. These flowers have high ultraviolet reflectance that draws bees in. Bees also favor flowers with bullseye ultraviolet patterns and other nectar guides.
Why are bees attracted to yellow and purple flowers?
Bees are highly attracted to yellow and purple flowers because of their perception of color. Yellow excites their green photoreceptors, while purple stimulates both blue and ultraviolet receptors. This makes these colors very visible and appealing to bee vision.
Do bees like pink flowers?
Bees do not see the color pink very well. Pink flowers appear light gray or lavender to bees. Since pink flowers reflect very little ultraviolet light, they are not highly attractive to bees.
What color do bees hate?
Bees tend to avoid very dark colors, especially black or blackish-red flowers. Solid crimson, maroon, brown, and black flowers are unappealing to bees since they offer low color contrast. Bees also cannot see the color red, so red flowers are not attractive to them.
Do bees like white flowers?
Bees will visit open white flowers, especially ones with ultraviolet nectar guides. But generally white flowers are less attractive to bees than more colorful blooms. Solid white provides little contrast which makes it hard for bees to distinguish shapes and patterns.
Charts and Graphs
| Color | Appeal to Bees |
|---|---|
| Purple | High |
| Violet | High |
| Blue | High |
| Yellow | High |
| Orange | Moderate |
| Green | Low |
| Red | Low |
Bee Color Vision Range
| Color | Wavelength (nanometers) |
|---|---|
| Ultraviolet | 300-400 |
| Violet | 400-450 |
| Blue | 450-500 |
| Blue-Green | 500-550 |
| Green | 550-600 |
| Yellow | 600-700 |
Key Takeaways
- Bees see colors in the ultraviolet, blue, and yellow/green range.
- Their color vision is tuned to see flower colors like purple, violet, blue, and yellow.
- Bees are attracted to patterns like ultraviolet nectar guides.
- Red, orange, pink, black, and gray flowers are not highly attractive to bees.
- Selecting a diverse range of vivid blue, purple, and yellow blooms attracts pollinators.
