How come dodo is brown instead of blue, green, yellow, purple or black or something?
361738
Bile is actually yellowish, the brown colour is a result of the digestive processes as it passes through the small & large intestines.
640682
Wrong!\n\nSee:\n\nhttp://www.abc.net.au/rn/science/ss/stories/s1330617.htm\n\neg:\n\n"Now since the dog’s eye is tuned for night, at night with low intensity levels you really don’t need very much in the way of colour. But of course dogs also hunt during the day, so what evolution has done is, you know, everybody gets the feeling that dogs are colour blind and somehow or other they see just in shades of grey. Well that’s not the way the game is set up. Dogs actually do have some colour vision, it’s just they have less colour vision that we do and they see fewer colours and they are probably a lot weaker than ours. So the dog sees the world in shades of blues and greys and oranges and yellows and the darker yellows might sort of fade down to something which we might call a brown, but they don’t see the oranges or the reds, they don’t see the greens and that sort of thing.\n\nIt drives me absolutely crazy. Right now the favourite colour for dog toys is red or that bright safety orange which you see in traffic columns and safety vests and that sort of thing. Well the thing is - to the dog’s eye that red is the same colour as the grass which the toy is supposed to land on, the only difference is that it’ll appear to be a little bit darker so it’ll be a slightly more brownish yellow than the yellow of the grass. So you buy this new toy and you throw it and Lassie goes tooling past it and you say to yourself, My God, my dog’s become an idiot or it’s just being obstreperous. Well no, the colour was there to catch the human eye: it’s absolutely useless with an dog’s eye. You’d be better off with blacks and whites."\n\nMore on the page, about dog senses.
14575
Eye color is a complicated trait, because it is controlled by several genes. It is likely that all of the genes have not yet been found. So far, scientists have a model in which one gene can either be blue or brown, with brown being dominant, and the other gene being blue or green and green being dominant. The brown trait from the first gene overrides either blue or green on the second. So, if someone has the brown trait, they have brown eyes. This model obviously fails to explain hazel, gray, and various other multi-shaded eye colors.\n\nWhat these genes do is turn on melanin production in the eye, the same thing that determines skin color. The more melanin, the darker the eyes. The reason a baby's eye color changes is it is born with very little melanin, both in its skin and in its eyes. As it is exposed to sun, melanin production increases until they've reached the skin and eye color their genes code for.\n\nThis is unrelated to hair color, which is controlled by several genes as well.
1130932
any three colors mixed together gives you brown.
283903
Calicos are white, brown and black. They're usually female.  I had one who lived to be 16.
301439
i actually think that dinos were blue.  btw, thanks for telling the rachiepie person that she was mean to me, i actually dissed her back too.  just wanted to let you know.
806627
This is partially true, partially false.\n\nWith regards to purple, most people would agree that purple light is always some mixture of reddish and bluish light.   I.e. you can imagine two knobs, one raising and lowering the red and the other raising and lowering the blue, and you can get many shades of purple.  There may be other hues added in as well, but there is *always* red and blue (if not, we rarely call it purple).\n\nIn other words, if we didn't have the word "purple" in our language, we would probably call it something like "reddish blue" or "bluish red".\n\nBut we cannot do the same with red and green.   We have a very hard time imagining, or pointing to, a color that is "reddish green".  If given only a red and a green knob, the result will be make the color more or less neutral (gray or white).\n\nLikewise with blue and yellow.  (Some people will respond that green is bluish yellow, but that's because many people are used to mixing pigments on paper ... we're talking about mixing lights.)\n\nThese two pairs,  red-green and blue-yellow, are *fundamental* pairs.  We call them "oppositional".  (There is also a third opponent pair ... light-dark ... but as we're just talking about color here, we can ignore that one for the moment.)  This is called the "opponent theory" of color vision and is associated with Ewald Hering.\n\nSo in that sense we can call these four colors "fundamental" hues"  because all color we see can be mixed using knobs of these four colors.\n\nPeople will also wonder about the red-green-blue primaries, and the fact that we know we have red, green, blue photoreceptors in our eyes.  These would also seem to be fundamental hues (as evidenced by the computer monitor on which you are reading these words ... that monitor is able to simulate a wide range of colors using just red, green, and blue).\n\nThese two theories ... the "opponent theory" and the "trichromatic theory" competed for a long time until we found a way to reconcile them.  Basically, we have three types of photoreceptors, but they are wired in a way in our retina, that by the time signals are travelling down our optic nerve, the red-green are antagonistic signals as are yellow-blue.
241218
Aqua is blue and green.\nMaroon is a deep red.\nMany males are stricken with color-blindness.\nConsider that it could be.
704581
Not rare, just not as common as blue or brown.
813043
orange, purple, silver, turquoise,\n\nand cage rhymes with beige
650831
Light blue and brown have always been a great combo, and a favorite of mine. I think the brown gives a nice balance to the blue, especially for Springtime. A little pink would be a nice accent too. Good luck!
838431
This is a genetic matter\nIt depends to you mother and father's eye chromosomes\nAt first humans they used to have brown eyes.\nWith mutations in chromosomes, colors like \nblue, green, black, hazel were developed.
480673
The chameleon has several cell layers beneath its transparent skin. These layers are the source of the chameleon's color change. Some of the layers contain pigments, while others just reflect light to create new colors.\n\nSeveral factors contribute to the color change. A popular misconception is that chameleons change color to match their environment. This isn't true. Light, temperature, and emotional state commonly bring about a chameleon's change in color. The chameleon will most often change between green, brown and gray, which coincidently, often matches the background colors of their habitat.\n\nAnother interesting fact about the chameleon is that they can move their eyes in two different directions at the same time! Creepy, huh?\n\nHere's a link to an interesting article about the chameleon from our friends at PBS.
612303
Don't know, but the brown colour of excrement is caused by a compound called bilirubin (not sure of the spelling) and this is a hydrogenated porphyrin. Porphyrinato compounds can lose energy by oxidising and the part in contact with the air could do this more rapidly and hence change colour. Not sure though.
1029267
doodee?  seriously?\n\nnot sure how this related to biology, since biology is the study of LIVING things.\n\nbut what else could be brown and red?  a robin?
310508
anks got a bit mixed up\n\nrichard__red\nof________orange\nyork_______yellow\ngave________green\nbattle________blue\nin____________indigo \nvain___________violet
819110
color of our skin.\nmine is brown.