Flowers Have Secret Blue Malos That Bumblebees Can See 1 Roses are red, violets not. They're, er, violet. 2 True blue flowers are exceedingly rare, and not for lack of effort.Plant breeders have repeatedly tried to nudge roses and chrysanthemums into blueness, but doing so is really hard (at least.without the use of dyes). These flowers get their colors from pigments called anthocyanins.which typically look pink or red, A flower must chemically tweak these pigments to make them bluer, and even if they did, the results are essentially purple. 3 Only a few flowers, like comflowers and Himalayan blue popples, have achieved true blue, and all by using special chemical tricks like adding metals to their pigments, or making their petals more alkaline, "All of this is chemically quite difficult and not many species have evolved the enzymes to do it."says Beverley Glover from the University of Cambridge. "Even with genetic modification, people have managed to make purple, bluish roses, but true blue isn't happening." 4 So imagine her surprise when she found that many flowers have secros. blue halos in their flowers. 5 The halos are rings at the bases of the flowers' petals. Sometimes they're visible to us, especially if the petals are dark. But in most cases, they're so faint that we can't see them. Glover only detected them with the aid of laboratory equipment, And yet, they're there-and they're visible to bees, whose eyes are more sensitive to blue wavelengths of light than ours are. zoo Which detail from the passage best explains what makes flowers with blue halos different from blue flowers without halos? 1. "genetic modification" (Paragraph 3) 2. "If the petals are dark"(Paragraph 5) 3. "microscopic structures" Paragraph 7) 4. "a black, purple or red base" (Paragraph 12)