# The Rarity of Blue **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [December 9, 2011, 6:08pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647 "2011-12-09T18:08:16Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![qazwart](https://avatars.discourse-cdn.com/v4/letter/q/5fc32e/32.png) [@qazwart](https://boards.straightdope.com/u/qazwart)\ **Post date:** [December 9, 2011, 6:08pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/1 "2011-12-09T18:08:16Z")
Blue is a rare color in nature, and because it is, many creatures use blue to attract their mates. Many species of Bowerbirds heavily decorate their bowers in [blue](http://farm4.static.flickr.com/3251/3063476368_389de2a9c2.jpg) even if it means [needing a little help from mankind](http://www.s-cool.co.uk/a-level/assets/learn_its/alevel/psychology/determinants-of-animal-behaviour/evidence-for-the-evolution-of-behaviour/bowerbird.jpg). Bowerbirds use blue to show their potential mates their ability to scrounge for resources. It _proves_ physical fitness if a male bowerbird can get blue objects, and keep other bowerbirds from stealing them. ---
**Author:** ![DORFMONT](https://avatars.discourse-cdn.com/v4/letter/d/2bfe46/32.png) [@DORFMONT](https://boards.straightdope.com/u/DORFMONT)\ **Post date:** [December 9, 2011, 6:15pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/2 "2011-12-09T18:15:24Z")
Thank you for answering one of my most puzzling questions: Why is there no blue food? Many years ago when I was a kid and making dinner for the family that night, I put blue food coloring in the croutons in the salad. It had every other color in it - why not blue? Everybody commented about it and were picking the little blue squares out of their salad before they ate it. Years later when I was discussing blue food with a friend, also an engineer, he went home and baked a blue chees cake and brought it to me. I cut a slice and ate a few bites, then put the rest of it in the refrigerator with the cake. Four months later I threw the whole mess out. There is no blue food because we won’t eat it. Now drinking is another issue altogether. ---
**Author:** ![Wallenstein](https://avatars.discourse-cdn.com/v4/letter/w/b5a626/32.png) [@Wallenstein](https://boards.straightdope.com/u/Wallenstein)\ **Post date:** [December 9, 2011, 6:18pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/3 "2011-12-09T18:18:10Z")
Link to column: > **[Why is there no blue food?](https://www.straightdope.com/21344119/why-is-there-no-blue-food)** Alfred Hitchcock once served all-blue food at a dinner party and noted that people really struggled to eat it. ---
**Author:** ![Wallenstein](https://avatars.discourse-cdn.com/v4/letter/w/b5a626/32.png) [@Wallenstein](https://boards.straightdope.com/u/Wallenstein)\ **Post date:** [December 9, 2011, 6:25pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/4 "2011-12-09T18:25:12Z")
We’ve also discussed this a couple of times on SDMB: > **[Blue Food?!](https://boards.straightdope.com/sdmb/showthread.php?t=177322)** > > I was recently discussing the Heinz blue ketchep with a friend, and why most people seem to find it disgusting. Anyway, we speculated that the reason for the failure is a noted lack of blue food in nature. Try as I might, I really can’t think of any... > **[Blue Food...?](https://boards.straightdope.com/sdmb/showthread.php?t=83148)** > > This has always puzzled me… Looking through a typical supermarket fruit ‘n’ veg section one can see naturally occuring foods of nearly every colour and hue in the rainbow with the exception of bright blue. There are, for example, bright green... > **[Why are there no BLUE food](https://boards.straightdope.com/sdmb/showthread.php?t=8844)** > > Why are there no blue food? ---
**Author:** ![qazwart](https://avatars.discourse-cdn.com/v4/letter/q/5fc32e/32.png) [@qazwart](https://boards.straightdope.com/u/qazwart)\ **Post date:** [December 9, 2011, 8:20pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/5 "2011-12-09T20:20:12Z")
> [@Wallenstein](#): > > Link to column: > > [Why is there no blue food? - The Straight Dope](http://www.straightdope.com/columns/read/3026/why-is-there-no-blue-food) > > Alfred Hitchcock once served all-blue food at a dinner party and noted that people really struggled to eat it. Oops. Sorry about that. I usually try to remember to add the link to my posts. ---
**Author:** ![dokcal](https://avatars.discourse-cdn.com/v4/letter/d/f14d63/32.png) [@dokcal](https://boards.straightdope.com/u/dokcal)\ **Post date:** [December 9, 2011, 8:43pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/6 "2011-12-09T20:43:59Z")
I’m sure somebody will correct me on this, but isn’t the opposite of purple _yellow_, and the opposite of blue, orange? I think Cecil’s color wheel got shifted a notch… or is this one of those additive / subtractive things? 😕 ---
**Author:** ![Ed\_Zotti](https://avatars.discourse-cdn.com/v4/letter/e/fbc32d/32.png) [@Ed\_Zotti](https://boards.straightdope.com/u/Ed_Zotti)\ **Post date:** [December 9, 2011, 9:35pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/7 "2011-12-09T21:35:01Z")
> [@dokcal](#): > > I’m sure somebody will correct me on this, but isn’t the opposite of purple _yellow_, and the opposite of blue, orange? You’re thinking of the complementary color wheel traditionally used by artists. The reasoning here was that opponent color processing (red/green and blue/yellow are the opponent color pairs) provided a physiological explanation for the prevalence of red/reddish edible plants in a green world. As Cecil concedes, however, this is conjecture. ---
**Author:** ![John\_W.Kennedy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_w.kennedy/32/1031_2.png) [@John\_W.Kennedy](https://boards.straightdope.com/u/John_W.Kennedy)\ **Post date:** [December 10, 2011, 3:10am UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/8 "2011-12-10T03:10:59Z")
MARY. I guess blue food is a turn off. —_Vanities_, Jack Heifner ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [December 10, 2011, 9:21am UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/9 "2011-12-10T09:21:41Z")
That picture of the Decaisnea fargesii fruit is startling. It looks unreal but you can find other online images that verify it really is that color. ---
**Author:** ![Arkcon](https://avatars.discourse-cdn.com/v4/letter/a/96bed5/32.png) [@Arkcon](https://boards.straightdope.com/u/Arkcon)\ **Post date:** [December 10, 2011, 12:23pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/10 "2011-12-10T12:23:52Z")
On the old Britcom _Chef!_,starring Lenny Henry, they remark that bandaids for food handlers are bright blue, to identify if they’ve fallen into the food. I’ve often seen the bright blue bandaid on cooks on TV. So, we’re pretty fortunate, that there’s no blue food. Its typical, for one of George Carlin’s rants to take on a life of its own but, for me, ever since I read or heard the joke, I always think, “Ha, Ha, George, but … no, _ **I** _ don’t want any blue food” I’ll eat blue fruits I might pick myself, but not a blue casserole. ---
**Author:** ![aruvqan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aruvqan/32/2891_2.png) [@aruvqan](https://boards.straightdope.com/u/aruvqan)\ **Post date:** [December 10, 2011, 12:44pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/11 "2011-12-10T12:44:56Z")
> [@Little\_Nemo](#): > > That picture of the Decaisnea fargesii fruit is startling. It looks unreal but you can find other online images that verify it really is that color. It says it produces pods full of a clear goop with little black beans embedded in it. Any idea what it tastes like? ---
**Author:** ![Gagundathar](https://avatars.discourse-cdn.com/v4/letter/g/a183cd/32.png) [@Gagundathar](https://boards.straightdope.com/u/Gagundathar)\ **Post date:** [December 10, 2011, 1:23pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/12 "2011-12-10T13:23:06Z")
“Clear goop”. Now THAT sounds yummy. ---
**Author:** ![ZenPyramid](https://avatars.discourse-cdn.com/v4/letter/z/ecc23a/32.png) [@ZenPyramid](https://boards.straightdope.com/u/ZenPyramid)\ **Post date:** [December 10, 2011, 7:50pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/13 "2011-12-10T19:50:22Z")
…blue steak, (presumably from blue cows)… ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [December 10, 2011, 9:02pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/14 "2011-12-10T21:02:59Z")
> [@aruvqan](#): > > It says it produces pods full of a clear goop with little black beans embedded in it. Any idea what it tastes like? No, I’ve never seen one other than in online pictures. But here’s a picture of the [beans](http://upload.wikimedia.org/wikipedia/commons/a/aa/Decaisnea_fargesii_Samen.jpg) and here’s a picture of the [goop](http://greffer.net/forum/images/uploads/autrevie/1186412341-botaniczny-zd1.jpg). ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [December 10, 2011, 11:52pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/15 "2011-12-10T23:52:16Z")
> [@ZenPyramid](#): > > …blue steak, (presumably from blue cows)… Served blue rare? ---
**Author:** ![Jeff\_Lichtman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jeff_lichtman/32/1531_2.png) [@Jeff\_Lichtman](https://boards.straightdope.com/u/Jeff_Lichtman)\ **Post date:** [December 11, 2011, 6:39am UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/16 "2011-12-11T06:39:26Z")
I noticed a factual error in the column: the inside of a blueberry is white, not purple. ---
**Author:** ![ZenPyramid](https://avatars.discourse-cdn.com/v4/letter/z/ecc23a/32.png) [@ZenPyramid](https://boards.straightdope.com/u/ZenPyramid)\ **Post date:** [December 11, 2011, 2:53pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/17 "2011-12-11T14:53:15Z")
> [@Saint\_Cad](#): > > Served blue rare? …aye. Under a good light it does actually look blue… ---
**Author:** ![Josh37](https://avatars.discourse-cdn.com/v4/letter/j/fbc32d/32.png) [@Josh37](https://boards.straightdope.com/u/Josh37)\ **Post date:** [December 12, 2011, 4:01am UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/18 "2011-12-12T04:01:48Z")
Jeff, you’re thinking of cranberries. Cecil, the color ranges from a purple red through purple to a dark blue. However, I think your explanation is incomplete. The earliest pigments that detected colored light in animals, detected the lower energy frequencies, i.e. red. The higher frequency pigments evolved later. In plants, more pigments arose covering the lower end of the spectrum than the higher. So, the best way to attract animals towards your fruit is towards the red end of the spectrum. This looks like a simple evolutionary bias towards “easiest first.” The test(s) would be a planet with life whose atmosphere had a different optic window. Finally, while not universal. the dearth of pigments that can harvest “green” light continues to be a bit of a puzzle, though it is probably just an artifact of the evolutionary process. ---
**Author:** ![Jeff\_Lichtman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jeff_lichtman/32/1531_2.png) [@Jeff\_Lichtman](https://boards.straightdope.com/u/Jeff_Lichtman)\ **Post date:** [December 12, 2011, 6:32am UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/19 "2011-12-12T06:32:46Z")
> [@Josh37](#): > > Jeff, you’re thinking of cranberries. No, I’m not. If you cut a raw blueberry in half you will see that the interior is white, or pretty close to it. [Here](http://www.istockphoto.com/stock-photo-1741150-blueberry-half-cut.php) is a photo I found of a blueberry cut in half. Blueberries and cranberries are pretty closely related, by the way. They are both in the genus _vaccinium_. ---
**Author:** ![Josh37](https://avatars.discourse-cdn.com/v4/letter/j/fbc32d/32.png) [@Josh37](https://boards.straightdope.com/u/Josh37)\ **Post date:** [December 12, 2011, 3:14pm UTC](https://boards.straightdope.com/t/the-rarity-of-blue/605647/20 "2011-12-12T15:14:56Z")
Jeff: As your link shows the interior of a blueberry is green(ish), bilberries and huckleberries are purple (Cecil), cranberries are white(ish). > **[Two Half Cranberry On White Background Stock Photo 38280790 | Shutterstock](https://www.shutterstock.com/image-photo/two-half-cranberry-on-white-background-38280790)** > > Find Two Half Cranberry On White Background stock images in HD and millions of other royalty-free stock photos, illustrations and vectors in the Shutterstock collection. Thousands of new, high-quality pictures added every day. If you’ve ever made whole cranberry sauce and blueberry cobbler for the holidays in North America, you would see the difference. As there are several hundred species in _Vaccinium_, many with edible berries, there is a lot of confusion, compounded by location and marketing. [Next page](https://boards.straightdope.com/t/the-rarity-of-blue/605647.md?page=2)