How many colours in a rainbow?

Vein=Violet that is the order of the 7 colours of the

Richard Of York Gave Battle In Vein
7.. Red, orange, yellow, green, blue, indigo, and violet

i'm not sure, but i'm gonna guess and say seven
Are you some kind of idiot?
seven - red orange yellow green blue indigo violet
Red and Yellow and Pink and Green, Purple and Orange and Blue. I can sing a rainbow, sing a rainbow sing a rainbow too.
Ok that's 7
red, orange, yellow, blue, indigo,and violet
not sure? i know there isnt a pot of gold though, all afternoon and cudnt find it, my new white trainers turned green in the grass too
Richard Of York Gave Battle In Vain.
there are actually more than 25 colours in a rainbow
This site has a lot of information about rainbows, including all the different shades we see. that definitely exceed 7.
Richard Of York Gained Battle In Vain . Thats how i remember it.
Traditionally 7, as the others have said, but in reality, wouldn't it be infinite? Surely every frequency in between would be represented as a continuum, with us just perceiving a difference every so often (i.e. what we think of as the next colour in the rainbow).
somewhere over the rainbow!! lol yeah richard of york gave battle in vain
depends on what drugs you've been taking!
all of 'em
7: Red, Orange, Yellow, Green, Blue, Indigo, Violet.
7!!! didn't u get that nursery rhyme at school...
oh n just in case Ur wondering other important one is..
30 days has September, April, June and November all the rest have 31 except Feb which has 28 but in a leap year 29!
as many as you can put names to-almost infinite
Infinite as each colour fades to the next
More than you can see (because it is a refraction of light, and the colors keep blending from one to another rather than being individual bands of defined colors) although our common perception is that of 7 colors:

"Even though a rainbow spans a continuous spectrum of colours, traditionally the full sequence of colours is most commonly cited as red, orange, yellow, green, blue, indigo and violet. It is commonly thought that indigo was included due to the different religious connotations of the numbers six and seven at the time of Isaac Newton's work on light, despite its lack of scientific significance and the poor ability of humans to distinguish colours in the blue portion of the visual spectrum.

A rainbow does not actually exist at a location in the sky, but rather is an optical phenomenon whose apparent position depends on the observer's location. All raindrops refract and reflect the sunlight in the same way, but only the light from some raindrops reaches the observer's eye. These raindrops are perceived to constitute the rainbow by that observer. The position of a rainbow in the sky is always in the opposite direction of the Sun with respect to the observer, and the interior is always slightly brighter than the exterior. The bow is centred on the shadow of the observer's head, or more exactly at the antisolar point (which is below the horizon during the daytime), appearing at an angle of approximately 40°–42° to the line between the observer's head and its shadow. As a result, if the Sun is higher than 42°, then the rainbow is below the horizon and cannot be seen as there are usually not enough raindrops between the horizon (that is: eye height) and the ground, to contribute."
There are seven colours in a rainbow:
These constituent colour make up waht we call white light. Apart from these, there are ultra-violet and infra-red which are invisible to the human eye
There are seven colours in a rainbow They are
ROY G BIV - now that brings back memories.

Yes it's 7
16 Colors

8 main colors and 8 Sub-colors.
According to Isaac Newton the colors of the rainbow are Red, Orange, Yellow, Green, Blue, Indigo and Violet - 7.
Depends what song you sing- a xmas rainbow fills the sky so count the colours you see, there is orange red and green and blue and indigo Violet to, or red and yellow and pink and blue ornage and purlpe and green, or red orange yellow green blue indigo vilote
7 colours which are visible to the naked eye. red orange yellow green blue indigo (a dark blue) and violet. They are traditionally remembered by Richard of York gave battle in vain but my pupils used to love Run Over Your Granny Because It's Violent