My mom, who speaks English as her second language, brought up this intriguing question posed by one of her former classmates. In English we have light green, light blue, light yellow, etc. So why do we call it pink instead of light red?
i think its just that it is a completely different red.
Because put light blue next to blue (i know my words are a bit sketchy but bare with me) and you know they are related.
But pink and red dont seem as ‘related’ as light blue and blue.
if you know what i mean.
My best guess on the answer is this.
What makes pink different from light blue, green, yellow, etc? What is there in nature that is important to us, that is pink or becomes pink?
Well, for those of us with lighter skin, strong emotions cause blood to rush to our faces and turn us pink. Blushing, anger, love, or fever make a pale or tan skin go…pink. It’s very important to us as a species to be able to describe or think about someone’s facial expressions including their skin tone, because that’s an important social clue. The reason we have a word for pink that’s not related to red is so that we can differentiate between the concepts of red (someone is bleeding, has been fighting, etc.) and pink (blushing, angry, but not hurt).
Of course, that’s my answer as a pasty-white person, your mileage may vary.
Corr
Pink generally looks different to ‘light red’ because it has some blue in it - grab some paints, and in one spot mix white with red, and in another mix white with red and a smidge of blue. Adding the blue leads to a more ‘lolly’ or ‘candy’ pink than ‘light red’ produces. So one might argue pink is it’s own colour, considering it has darker shades such as magenta.
We do have some other names for pale colours - lilac rather than light purple, mint rather than light green, lemon rather than light yellow, apricot rather than light orange. In those cases we’ve drawn names from nature.
I’m aware of flowers called Pinks, but I guess they’re named for the colour 
Any etymologists to help us on the origin of the word ‘pink’ here?
Snaf
About color words in general, I suggest you see Cecil’s column about Could early man only see three colors?. In it, you will notice that pink is one of the 11 basic color words of English. Not every language has the equivalent of pink as a basic color word, though.
If you are really interested in basic color words, I suggest you read Berlin and Kay which Cecil refers to. If you can’t find it in the bookstore, the library probably has a copy.
SnowCat66, what language is your mother’s native tongue? I can tell you if it’s covered specifically by B&K.
About the etymology of pink, Snaf has it backwards. The color comes from the flower.
On a related topic, my father works as a Chemistry Professor in a college in South Africa and has a lot of African (from all over Southern Africa) students who consistently refer to the colour change that occurs in a Phenolphthalein titration (which turns a vibrant pink colour) as having turned “orange”. So it seems that there is some degree of colour definition or recognition that is culturally or linguistically based.
Gp
IIRC It’s the other way around; the colour pink is named after the flower; I’ll try to find a cite.
Here we go:
http://www.writersblock.ca/summer98/a-letter.htm
Well, maybe I’m wrong, but… in the pink would refer to either systems in, say, in aircraft or spacecraft, having to do with colors and marking used on instruments for indication; or it would refer to meters or measures that are marked within a desirable range for whatever it is they’re measuring (blood oxygen maybe?). The first seems more likely, though the second is possible. Maybe both. Maybe neither. This is entirely speculation. Correct me if I’m wrong!
I thought the expression in those cases was that the instruments are reading ‘in the green’.
Finnish- and you’ll note that the word for pink is “vaaleanpunainen” or “light red”.
Aircraft instruments have 3 main colours:
Red (no go areas)
Yellow (caution areas)
Green (safe operating areas)
Blue and white are also used to indicate critical values such as airspeeds, but in my experience (yes I am a pilot) pink is not used (or if the colour does happen to be pink it’s still reffered to as red) and so the above is not likely to be the origins of “in the pink”.
Why does anybody care?
Because:
Pink it’s my new obsession
Pink it’s not even a question,
Pink on the lips of your lover, ‘cause
Pink is the love you discover
-‘Pink’, Aerosmith
Ya know, I was wondering about that… seemed odd to me that there would be pink instruments to mean “good.” Still, it was a theory :D.
Unfortunately, Berlin and Kay did not study Finnish color words, so I can’t tell you what stage they think the language is in.
But from some web research (here), it seems that Finnish is a stage VII language with 10 basic color terms: (the equivalents of) black, white, red, green, yellow, blue, brown, orange, purple, and grey. (Stage VII languages have between 8 and 11 basic color terms.)