According to Bee Culture, the most likely colors to attract bees are purple, violet and blue. ... Thanks to ultraviolet patterns on flowers that direct bees to where the nectar and pollen are stored, bees are able to follow these UV bull's-eyes straight to the sweet stuff, regardless of the color of the petals.
Do bees prefer blue or purple flowers?
Bees' color preference drives flowers to evolve a blue glow
Many wild bees prefer flowers in the violet-blue range—in part because these blossoms tend to produce high volumes of nectar. But it's not easy for plants to produce blue flowers.
Do honeybees like purple?
Colour, shape, scent
Bees' vision is very different from that of humans. They can see colours at the yellow and blue ends of the spectrum most easily, which is why mostly they're attracted to white, yellow, purple, and blue flowers.