"The Invisible Pink Unicorn (IPU) is the goddess of a satiric parody religion aimed at theistic beliefs, which takes the form of a unicorn that is paradoxically both invisible and pink. These attributes intend to satirize the contradictions in properties that some attribute to a theistic diety; this makes her a common rhetorical illustration used by atheists and other religious skeptics. The IPU is commonly used to highlight the perceived fallacious or arbitrary nature of supernatural beliefs by, for example, replacing the word "God" in any theistic statement with "Invisible Pink Unicorn". A quote from the alt.atheism FAQ sums up this use of the Invisible Pink Unicorn: "The point of this silliness is to prod the theist into remembering that their preaching is likely to be viewed by atheists as having all the credibility and seriousness of [the atheists'] preaching about the IPU." It is accepted that there are no actual believers in this mock goddess, but it has become popular, especially on atheist web sites and on-line discussion forums, to feign belief in her both for the sake of humor and as a form of critique or satire of theistic belief. These professions of faith intend to demonstrate the difficulty of refuting avowals of belief in phenomena outside human perception." "Invisible Pink Unicorns are beings of great spiritual power. We know this because they are capable of being invisible and pink at the same time. Like all religions, the Faith of the Invisible Pink Unicorns is based upon both logic and faith. We have faith that they are pink; we logically know that they are invisible because we can't see them." Source and further information: http://en.wikipedia.org/wiki/Invisible_Pink_Unicorn

Because Pinkness is essential to being an Invisible Pink Unicorn. If She were not Pink, she would not be an Invisible Pink Unicorn. But our faith tells us that She is the true IPU. Since we can conceive of the IPU, she must be Pink, because non-Pinkness would be a blemish, and the IPU is without blemish.

Because my Invisible Purple Dragon said so!

If it was invisible it would be clear and have no color whatsoever.

Its name tells us.

Because it is the invisible PINK unicorn. But then again, you really don't know....hmmmm...

Because it is not possible for it to be any other color after all it is invisible

My faith tells me she is Pink, therefore she must be pink - for what my faith tells me (what I believe in...) must be true. Faith is Truth...

even though invisible , it leaves a pink taste in your mouth when it wonders by!

The Unicorn works in mysterious ways.

Because Cheetahs have been chasing that bastard for millennia, and they're pink colorblind, or they would have caught it. That also explains how IPU can be pink and invisible at the same time

The answer is in the invisible scriptures that only The Man In The Funny Hat is able to read. I'll ask him next time we play cribbage.

'Cause if it was white we'd be calling it the Invisible WHITE Unicorn!

Well it's because the religious text says so. The invisible pink unicorn sent his visible daughter down to earth in human form to tell of it's existence and being pink, while sleeping with all of the gullible men who believed her. Now you better believe in the invisible pink unicorn and become who it wants you to be or else you will suffer FOR EVER!!! HAHAHA, I AM GOD

How do we know it's a unicorn either?

Belief in the Invisible Pink Unicorn (Blessed be her holy hooves) is based in both logic and faith. I have faith that she is pink but since I cannot see her, logic tells me that she is invisible.

Faith, of course!

we are just playin it by ear, for know. :D

Because somebody told you and that's all there is to and that's all it takes

That's simple, drop some acid (LSD) and find out for yourself.

Rigid Truth in Advertising Laws.

The same way we KNOW that God the Father is both a spirit AND a male.

That's where your faith comes in, she died for our sins so we must not question her.

The secret clue is in its name...