The rainbow,as we know it,is Red,Organge,Yellow,Green,Blue,Violet.ROYGBV,I'm ignoring Indigo because,let's be honest,Indigo?But where exactly is violet? Is it at the end here?This dark blue? And what's this brighter light blue-green ?Cyan,perhaps?Why don't we say the rainbow is Red Orange Yellow Green Cyan Blue?
彩虹的颜色嘛 当然是红橙黄绿蓝紫 ROYGBV 我把靛省掉了，靛色 逗我呢？那么紫色哪去了呢？是在这深蓝色最末端吗？这个浅蓝绿色是啥 青色嘛？为啥我们不说彩虹是红橙黄绿青蓝（木有紫）的呢？
ROYGCB Well,we actually do,and we've just forgotten.When Isaac Newton originally observed a rainbow of light split by a prism and made his labeling of the colors as RedOrangeYellowGreenBlueIndigoViolet,the thing he called "blue"was indeed what we would now call blue-green,teal or cyan-reminiscent of the color of the blue sky.
ROYGCB其实 我们曾经的确这么说，当牛顿最初通过棱镜观察散射的彩虹光并为颜色标上“红橙黄绿蓝靛紫”时，他们所说的“蓝”是我们今天所指的蓝绿色 或说青色 让人思绪无穷的天空的颜色。
And what we now tend to call blue,Newton called violet as in,roses are red,violets are blue,Dark blue.He only included indigo in his fundamental"seven colors of the rainbow"so that they would match the number of notes of the western musical scale:Do re mi fa so la ti...yeah.
我们今天所说的蓝在牛顿口中是“紫”就是 红玫瑰 紫罗兰 也就是深蓝色。他在“七色彩虹”中引入靛色 只是为了和西方的音乐音阶数量相配：哆来咪发嗦啦啼 就酱紫。
Purple and magenta,as we know,don't occur in the rainbow from a prism because they can only be made as a combination of red and blue light,and those are on opposite sides of the rainbow,nowhere near overlapping.So there's no purple or hot pink in the rainbow from a prism.Violet is there in the "roses are red,violets are BLUE"sense,but purple is not.
正如我们所知 紫色和品红并不在棱镜折射出的彩虹里 因为它们只能通过红蓝光叠加产生，而这两者在彩虹的两端 完全不可能叠加嘛。因此 棱镜折射出的彩虹中没有紫色或亮粉色。“红玫瑰 紫罗兰”中有蓝紫色 但没有紫色。
So then why do rainbows in the sky often look like they have pruple in them? I suspect sometimes it's an optical illusion whereby nice deep blues in small amounts surrounded by a lighter color appear purplish to our eyes.However,sometimes purple and pink really are there,because a rainbow is really a rain-disk:each color of sunlight reflects back in a bright rimmed disc,all of different sizes,which together add up to make a white disk with a colorful rim.
那么 为啥天上的彩虹看上去有紫色呢？我认为 这可能是一种视错觉 小面积的深蓝被亮色环绕时看碟上去像是紫色。不过 有时紫色和粉色真的出现过，因为彩虹终究还是“彩蝶”，日光中的每一种颜色反射在光边盘上 环大小各不相同，它们叠加在一起 形成有着彩色边缘的白碟。
But because light is a wave,interference from the raindrops themselves actually gives each disk multiple rings:the familiar outer ring is just the brightest.The others are called"supernumerary rings"and are the source of supernumerary rainbows.The smaller the raindrops,the stronger the supernumerary bows.And if the drops are the right size,the first red supernumerary ring can overlap significantly with the main dark blue ring,and what do red and blue give?Purple!
由于光的波动性 兩滴产生的干涉使彩碟出现多个环 我们所熟悉的外环是最亮的一个，其他的被称为“多余环”是多余虹的起源。雨滴越小 多余虹越明显。如果雨滴大小恰到好处 第一个红色多余环会叠加在主环的深蓝环上 ，红加蓝等于 紫色！
So as the saying goes,roses are red,violets are blue,and purple in a rainbow is a supernumerary hue.
所以 正如俗话说 红玫瑰 紫罗兰，蓝紫的彩虹 就是多余环。